Three weeks in the process of discovering Thailand? Sounds like an exciting adventure. Instead of trying to tick off all the places on the map, it is far more pleasant to enjoy the country's best at a relaxed pace. Compare to just 2 weeks, 21 days is enough to see all the highlight without exhausting yourself.

We’ve put together a Thailand itinerary 3 weeks that takes you from Chiang Mai to Bangkok and then down to the Andaman Sea, with a couple of islands like Koh Phi Phi included in between. You’ll find ideas for what to see and do, plus a printable plan to make your trip easy to follow. In case you’re ever thinking about a shorter getaway, have a look at our 10-day Thailand itinerary, as it might suit your plans just as well.

Scroll down to the end to grab a free travel itinerary.

Quick headup before spending 3 weeks in Thailand

• For 3 weeks, pick around 3 major places you want to go. Then pencil in a day trip or two. Don’t overthink it.

• Most Western nationalities (US, UK, EU, Australia, etc.) currently get a 60-day visa exemption on arrival (increased from the previous 30 days). You do not need to apply beforehand if you are from an exempt country.

• Thailand is still affordable, but "tourist pricing" has risen. See the detailed cost breakdown for travelling Thailand here.

• From November to February is the best time to visit. Here we talk in detailes the best time to visit Thailand depening on what you seek.

• Be sure to download Grab (Asian Uber), ViaBus, Google Maps, Agoda, Line, and your esim app.

• Getting around is superb easy. Domestic flights are cheap. There are many transporation: trains and Grab for city, buses/trains for longer distance, ferries for island hopping.

• Shoulders and knees must be covered at temples and sacred places.

• Stick to breathable, lightweight travel t-shirts. Thailand is really really hot. 

The 21-Day Thailand Itinerary (North to South)

This three-week travel guide to Thailand takes you from the green hills of the north to the lively cities in the centre, before finishing with a few days on the beaches of the southwest.

Week 1: Chiang Mai & Pai

Chiang Mai International Airport is the main entry point for travellers exploring northern Thailand. Depending on where you’re coming from, you may find a direct international flight; however, if not, it’s easy to fly into Bangkok first and connect from there.

We’d suggest visiting Chiang Mai and Pai between November and February, or early March, when the weather is cool and dry, and the cities are full of local festivals.

From February to April, it’s crop burning season. So you should swap Chiang Mai out to the Southern beaches (Gulf side is best) or Central Thailand.

Days 1: Arriving

For any kind of Thailand itinerary, it should goes like this: Bangkok, your second destination place, your third destination, Bangkok, then fly home.

The reasons we place Bangkok last is that we could chill and do shopping before going home. You don’t have to lug the sourveniers around. You don’t have to spend the last day transiting to Bangkok (which will eat a whole day). You are less likely to be overwhelmed by the hustle and bustle of the city first (unless that’s your cup of tea).

On the first day, you’re likely experiencing jet lag anyway (not to mention getting used to the heat).

Upon landing in BKK, you have several options: fly to Chiang Mai right away; take the overnight sleeper train to arrives in Chiang Mai by morning; or simply book an overnight hotel to recover.

But if you could book a straight flight into CNX and start your journey immediately, feel free to do so. This is the best case scenario but less common as there are more flights to Bangkok (and likely cheaper too).

Pro tip: Pack light with a CabinZero 40L+ backpack. It’s just the right size for what to pack for 3 weeks in Thailand and still small enough to take as a carry-on with most airlines. Plus, the water-resistant coating keeps your things safe when you get caught in a quick rain shower in Thailand.

Days 2-7: Chiang Mai

A more relaxed pace compared to Bangkok. Photo by Fokke Baarssen on Adobe Stock

Chiang Mai has so many places to stay, but we usually go somewhere close to the Old City. It’s such a nice area to stroll around, and being nearby means you can easily reach the temples surrounded by the old walls and moat.

One temple that really stands out is Wat Phra Singh, where you can find golden chedis and the Phra Singh Buddha statue. Wat Chedi Luang is another place we really recommend visiting. It was built to hold the ashes of King Saen Muang Ma’s father and other important relics.

Chiang Mai is also known for its elephants, and if you love these giants like we do, it’s a great idea to include an ethical elephant sanctuary visit in your trip.

What makes it special is that the elephants live freely in their natural surroundings. There’s no riding or performances, just walking with them, bathing them in mud and feeding them bananas.

When evening comes around, the Wualai Walking Street and Thaphae Walking Street markets are perfect for trying local food or picking up souvenirs. They’re open on weekends, but if your schedule doesn’t match, don’t worry. The Chiang Mai Night Bazaar opens every day and has everything from Pad Thai and Tom Yum to grilled crocodile.

Another lovely experience in Chiang Mai is joining a Thai cooking class. There are plenty to choose from, and you’ll learn how to make authentic dishes from scratch. We tried classes at Thai Akha and May Kaidee. Both offer vegetarian options and usually cost over one thousand baht per person.

2 Days Getaway (Optional): Pai

We say Pai is very much worth it. Photo by Goran on Adobe Stock

Before we first visited Pai, we’d heard very mixed things about it. Some people said it was too small, too ‘hippy’ and a bit pricey. Others absolutely didn’t want to leave, saying they felt at home among the mountains. For us, Pai turned out to be a peaceful town that definitely deserves a place in your 3 weeks in Thailand.

The easiest and cheapest way to get to Pai from Chiang Mai is by minivan. The journey takes about five hours and goes through winding mountain roads, so it might not be ideal if you get motion sickness. If you want a bit more comfort, just hire a driver or look for shared rides online. Or you can skip Pai altogether and look for more things to do in Chiang Mai.

Once you’re in Pai, make time to visit the White Buddha Temple (Wat Phra That Mae Yen). The big Buddha statue overlooks the valley, and although the climb up the stairs can be a bit of a workout (300 steps), the view from the top makes it worth it. The temple usually closes around 6 pm, so try to go before then.

Pai Canyon is another spot you shouldn’t miss. It’s a great place to take in the scenery. The trails can be quite narrow in some parts, so take your time, especially if you go for sunset. Be sure to grab some day hiking essentials.

And you might also want to visit Pam Bok Waterfall and the Bamboo Bridge. They’re close together, so you can do both in one trip. Entry to the waterfall is about 100 Thai Baht (THB) per person, and you’ll find the Bamboo Bridge just along the same road. The falls are stronger during the rainy season, whilst in the dry months their flow is fairly gentle.

Getting around Pai is best done on a scooter. It usually costs around 100 THB a day. Just make sure you have a valid licence; otherwise, your insurance won’t cover you if something goes wrong.

What to Pack

• Bring non-drowsy Dramamine if you get car sick. The road to Pai has 762 curves. It is notorious for making people sick. 

• Carry light hoodie/windbreaker. In Jan/Feb (mornings/evenings) or if you ride a scooter up a mountain, the North can actually get chilly (15°C–18°C).

• Insect Repellent (DEET) is a must. The jungle areas around Pai have more mosquitoes.

Week 2: Andaman Sea

It’s time for some fun under the sun. Photo by Fokke Baarssen - stock.adobe.com

Your second week in Thailand is all about enjoying the beautiful islands around Krabi, like Koh Phi Phi and Koh Lanta. Pack your sunglasses, swimwear, a towel and a hip bag for sunscreen and a bit of cash. There will be plenty of time for beaches, boat trips and lazy afternoons by the sea.

Day 8: Travel to the Thai Coast

The best way to do this is by flight. It’s cheap and easy enough to find a 2-hour flight from Chiang Mai to Krabi. In fact, Thai AirAsia offers non-stop flights from Chiang Mai (CNX) to Krabi (KBV). Prices start at ~900 baht during the low season, or up to 2,500 baht in peak season. The way to the airport is easy, too. Just catch a Songthaew or Grab from the Old City (20-40 min) to the airport.

Days 9-13: Krabi

We once thought Krabi was all about islands and beaches, but when we arrived, we were surprised to find there’s so much more to it than that. It has something for adventure seekers, culture lovers, and even those Thailand itinerary planners who are simply looking for a peaceful place to recharge.

For somewhere to stay, there are plenty of hotels near Railay Beach, but if you’re after something affordable, Sasi House in Krabi Town is a safe bet. It’s a small guesthouse with free Wi-Fi and Thai-style décor.

When it comes to the prettiest beaches in Krabi, Railay Beach is unbeatable. West Railay is ideal for a swim, and the east offers some good restaurants to eat at. Phra Nang Cave Beach and Tonsai Beach are also renowned for their relaxed vibe, and if you're lucky, you'll see glowing bioluminescent plankton at night.

This view can be yours. Photo by NIKCOA on Adobe Stock

Towards the far end of Phra Nang Beach, there is a small cave shrine called Princess Cave. Local myths tell of a lost princess, which is how the cave got its name. Inside, you’ll see many wooden carvings in distinctive shapes, believed to symbolise fertility and good fortune.

If hiking is on your list of favourite things, and it’s your first time in Thailand, the climb to Khao Ngon Nak Viewpoint (Dragon Crest Mountain) is unskippable. The view from the top is breathtaking, though the trail up is steep, slippery and a little tricky. It’s definitely not for the faint-hearted.

To round off your stay in Krabi, you might also like to explore some inland sights such as Wat Tham Suea (Tiger Cave Temple), the Khlong Thom Hot Springs, or one of the local Batik workshops like Dahla Batik and Varich Krabi Batik.

Okay, Krabi nightlife isn't as wild as Phuket's, but it is still everything that's going on, especially around Ao Nang with live music bars and pubs.

One of the places that we actually had a good time at is Boogie Bar, which is tucked away just off the main road on the beach. They have live bands every night. It is probably best not to arrive too early, as things don't actually get going until about nine at night. The band plays everything from old rock to the occasional ABBA number. And yes, they do occasionally let the guests up and play too.

Optional: Koh Phi Phi Day Trip

A boat or ferry is the only way to get from Railay to Koh Phi Phi. Fortunately, they run frequently and don’t take long, so there’s no need to worry about timing. You could spend a night here, as the party goes on all night.

Koh Phi Phi itself may not blow everyone away, but the Phi Phi Viewpoint and Maya Bay are definitely among the must-see places in Thailand.

Another highlight of the island is Pileh Lagoon. Long-tail boats gliding between limestone cliffs and water so blue will make a great setting for your next batch of photos. Swimming and snorkelling here are popular, too. We could already see plenty of colourful tropical fish from the boat before we even got into the water.

The Pileh Lagoon in Koh Phi Phi. Photo by Jo Panuwat D on Adobe Stock

During our day trip, we stopped for lunch at Koh Pai, or Bamboo Island, which is surrounded by coral reefs. There’s a small café and toilet facilities, and the shallow water is ideal for swimming, snorkelling, or simply relaxing on the sandy beach.

If you fancy mixing things up a little, you can continue from Phi Phi to Koh Lanta, known for its mangrove forests and rich marine life, then take a short ferry to Koh Jum, an island with plenty of seafood restaurants.

Optional: Day Trip or An Overnight in Khao Sok National Park

Getting from Krabi to Khao Sok doesn’t cost much. On our last trip, we took a minivan for about 325 THB per person. The ride took just over two hours. If you’re short on time, you can take a private transfer instead, though it’s quite a bit more expensive at around 2900 THB or more.

The steep limestone cliffs, clear rivers and the chance to see wildlife up close make Khao Sok National Park a real highlight of any trip. Spending two days and one night here was just what we needed to enjoy the park to the fullest.

The rainforest is vast and full of surprises, so it is best to book a guided tour with an English-speaking guide. You can do this directly through the national park website.

Most tours include a boat trip to spot wildlife, a walk through the jungle to hidden waterfalls, and a climb up to Kai Sorn Viewpoint. Don’t forget to wear long sleeves and trousers, as there are plenty of mosquitoes, insects and even leeches near the water.

Other enjoyable activities here include swimming, kayaking, seeing the Diamond Cave, or staying in a floating bungalow in Khao Sok Lake (otherwise known as Cheow Larn Lake).

Floating bungalows in Khao Sok National Park. Photo by Mazur Travel on Adobe Stock

What to Pack

• Brining along a dry bag is highly recommended. When island hopping by long-tail boat, water splashes everywhere. A dry bag keeps your phone/camera safe.

• Reef-safe sunscreen is expensive in Thailand (often $15+ for a small bottle). Bring your favorite brand from home.

• Water shoes is worth considering but not a must. Some beaches in the Andaman (like parts of Koh Lanta or Phi Phi) can be rocky/coral-heavy at low tide.

Week 3: Bangkok & Khao Sok

After leaving the south behind, your Thailand itinerary for 3 weeks takes you to the capital of the country.

Day 14: Travel to Bangkok

Don’t mind spending a little extra? Flying is the quickest way to go. But if you enjoy the journey as much as the destination, try an overnight sleeper train experience in Thailand. It’s not the most comfortable way to travel, but it’s a classic Thai adventure that lets you wake up in Bangkok ready to explore. The journey usually takes around 11 to 12 hours, and you can buy tickets online with ease.

A lot of backpackers base themselves near Khao San Road in Banglamphu. It’s full of budget places to stay, lively bars and street food. It’s right in the middle of the city, so it’s close to many of Bangkok’s main attractions.

Days 15-19: Bangkok

A couple of days isn’t really enough to see everything in Bangkok, but it’s just right for visiting a few landmarks and wandering through its famous markets.

Start with the Grand Palace, once home to Thailand’s royal family. Inside the grounds, you’ll come across Wat Phra Kaew, the Temple of the Emerald Buddha. Not far away are Wat Arun, the Temple of Dawn, and Wat Pho with its huge reclining Buddha. For food and a bit of shopping, head to Chinatown, the Ratchada Train Night Market or Chatuchak Weekend Market.

Bangkok also has a few museums that you might like to check out. They may not be as large as those in Europe, but each has its own character. The Bangkok National Museum displays royal costumes, old weapons and Buddhist art. The Museum Siam uses light, sound and interactive exhibits to explore what “Thainess” really means.

The mountains, the sea, now here come some urban vibes. Photo by stockphoto mania - stock.adobe.com

Day 20: Final Relaxing Day

Now is the chance to slow things down before the long flight home. Start with a late breakfast or coffee somewhere familiar, then keep the plan simple. Pamper yourself with a spa. Sample some foods from a random street stall. Shopping till you drop at the mega malls. Simply chill at a green cafe like Agalin Garden Room. There are endless things to do here.

Day 21: Leaving

And so it is, your sojourn in Thailand has finally arrived. After you have checked out, proceed to either Suvarnabhumi or Don Mueang for your return flight, or continue on with your Southeast Asia travel plan to explore other destinations in the region.

Get Your Free Thailand Itinerary

Before you leave, don't forget to download our Free Downloadable Thailand Itinerary. Print it out and carry it with you during your stay in Thailand. It'll tell you what to do next and where to go so that you won't waste any time.

Ready to Start Your Thai Adventure?

A 21-day Thailand trip is all about getting the balance of city life, culture, and island relaxation just right. We hope this guide to a Thailand itinerary 3 weeks makes planning that little bit simpler for you. With a handy lightweight backpack such as CabinZero, you can wander from temple to beach or walk through the jungle without ever feeling weighed down.

Quyen Pham