Bangkok rarely sleeps — the late-night food scene runs from street stalls to 24-hour restaurants.
Sam Yan's food court (SamYan Mitrtown), various On Nut shophouses, hospital area restaurants near Bumrungrad — genuine 24-hour spots.
Talad Neon, Rot Fai, and several Sukhumvit night markets wind down around midnight — still lively until then for hot food.
7-Eleven is always open — microwaveable rice dishes, fresh pastries baked in-store, hot dogs, instant noodles; not exciting but never closes.
A small number of Chinatown and Yaowarat stalls stay open until 3–4 AM; look for the lit shophouses with steam coming from the kitchen.