Fridays

Bophut - Fisherman’s village from 5 pm till 11pm first and largest on Samui and usually very busy if weather permit.  Large amount of street food and clothing as well as souvenirs and gifts.  The road is closed to traffic so find parking outside the village and walk on in  Allow a few hours to stroll around.  Most restaurants are open and enjoying the crowds

Saturdays 

Nathon [the capital] walking street is along a minor street between the main [one way] road and the beach road.  Starts around 5pm onwards.  Roads closed to traffic with prices usually a bit cheaper than other markets.  A great place to eat and shop, some different food is sometimes available here

Chaweng - Opposite the lake on the one way system and also near the northern end of the boundary wall for Centara Grand.  Both start around 5pm and small.

Sundays 

Lamai - main beach road from bridge to market area.  Starts from 5 pm onwards not as large as Bophut.  Road is closed to traffic along part of the main beach road

Mondays

Chaweng - Opposite the lake on the one way system and also near the northern end of the boundary wall for Centara Grand.  Both start around 5pm and small.is one big market every day 

Tuesdays

Chaweng - Opposite the lake on the one way system and also near the northern end of the boundary wall for Centara Grand.  Both start around 5pm and small.is one big market every day

Wednesdays

Choeng Mon - outside Muang Samui hotel.  Miniature floating market theme.  Open from 5 pm onwards along both sides of the main road, roads are not closed to traffic.  Quite a good variety of food and goods for a small village Market and worth a visit if you are in the area

Thursdays 

Maenam - main intersection down to  the beach.  Open fro 5pm onwards ,traffic is closed to the 2 side streets leading down to Maenam beach.  Relaxed and more laid back than Bophut and has a more local feel about it. Great selection of food and many times theres a show outside the Chinese temple 

Chaweng - has market type tourist stalls along the beach road daily.