Of the two Gulf islands we know best, Koh Samui is the easy one with children. It has an airport, so you skip the ferry with luggage and small humans. It has proper medical care, big supermarkets and family resorts with kids' clubs. And it still has the good stuff, jungle waterfalls, fishing villages, night markets and warm shallow water, that makes Thailand so rewarding for a family trip.
For the whole-island overview, see our Koh Samui guide. For choosing your beach, our Koh Samui beaches guide goes coast by coast.
The beaches that work with kids
Chaweng and Lamai are the big names, and both have long stretches of sand with places to enter the water. Chaweng is busier and louder, which suits families who want restaurants and shops nearby. Lamai keeps a slightly more relaxed tone. Sea conditions vary by season, weather and the part of the beach you choose, so check locally and supervise children closely.
Our favorites with children were actually the quieter ones. Choeng Mon in the northeast has a sheltered, almost lake-like bay at low tide that is ideal for toddlers and weak swimmers. Maenam on the north coast is wide, flat and calm with a village feel. And Bophut's Fisherman's Village gives you a swimmable beach by day and the island's best evening stroll by night.
Waterfalls and the green interior
Na Muang waterfall is a classic inland outing. The lower fall is easier to reach than the upper one, but rocks can be slippery and conditions change after rain. We enjoyed the cooler forest setting; check locally whether swimming is permitted and safe that day, and keep small children out of fast or deep water. We skipped the elephant attractions on the way in and never missed them.
The upper Na Muang fall is wilder and prettier, but the climb is steep and hot, so we saved it until our kids were older. The interior roads pass coconut plantations and viewpoints; a car or driver makes those stops simpler with children.
The Big Buddha temple at Bang Rak is an easy win with kids too. The causeway out to the island temple, the giant golden Buddha, the souvenir stalls and the drum-banging that children find endlessly funny make it a low-effort morning trip.
Boat trips worth doing with kids
Ang Thong Marine Park is the big one. Forty-plus limestone islands, a hidden emerald lagoon you climb to a viewpoint for, kayaks through caves and channels, and snorkelling stops. Full-day trips leave from Samui's piers early in the morning. It's a long day for small children, so we'd suggest it for roughly age six and up, and book a speedboat tour with a smaller group if your budget allows.
The short hop to Koh Phangan is an easier first boat trip, and the calmer north coast there makes a lovely day out. Our Koh Phangan with kids guide explains why many families split a holiday between the two islands.
Built attractions, honestly assessed
Samui has the aquarium, a butterfly garden, a snake farm, an animal zoo and various shows aimed squarely at families. We tried some and skipped others. The aquarium is small but fine for a rainy hour with young kids. The animal attractions vary wildly in how well the animals are treated, and we generally avoided the ones where you pose with wildlife. The better use of a hot afternoon, in our experience, was a resort pool, a beach, or the Friday walking street in Fisherman's Village, where the kids ate skewers and watched the fire performers.
Logistics: getting there and around
Flying direct into Samui is the low-stress option, though the open-air airport and limited competition keep fares higher than mainland Thailand. The budget route is flying to Surat Thani plus bus and ferry, which works but eats most of a day with kids.
On the island, shared pickup trucks serve many routes, while taxis and private drivers cover others. Confirm fares before setting out. We used scooters when we lived in the area, but Samui's traffic is busier than on Koh Phangan. For a visiting family, we would arrange a car or driver and ask about appropriate child restraints in advance.
A few practical notes. Know where the nearest clinic is before you need one, use mosquito repellent, and check sea conditions and warning flags daily. During rough weather, choose a pool or another land activity instead of assuming a sheltered beach will be safe.
When to come
January to June often brings better beach conditions, while later months can bring heavier rain and rougher crossings. Weather varies by year, so check a forecast and ferry notices close to departure. If you are combining islands, Samui makes an easy first landing before the ferry to Phangan.