Bangkok's smarter rooftops enforce dress codes: no flip-flops, no tank tops. The best rooftop bars in Bangkok climb highest at Alfresco 64, the open-air whisky terrace sixty-four floors up State Tower on Silom Road. Bar.Yard, forty floors up at Kimpton Maa-Lai on Soi Tonson, looks over Lumpini Park and warns that rain can take the outdoor seats. The Speakeasy Rooftop Bar Bangkok at Hotel Muse runs a retractable roof over its all-weather terrace. ABar Rooftop at the Marriott Marquis Queen's Park leans on gin, and Above Eleven Rooftop Bar & Restaurant on Sukhumvit Soi 11 mixes Lima and Tokyo on a Nikkei menu; book two days ahead for weekends. These are the bars we would start with.

A 1920s Prohibition-styled rooftop across floors 24-25 of Hotel Muse Bangkok Langsuan, its design and drinks inspired by King Rama V's European travel logs. The 24th floor carries a retractable roof; the 25th is open-air with private Secret Domes, a Secret Garden and The Blind Pig cigar lounge. Live DJs Thursday to Saturday, no cover. Smart casual.
ABar Rooftop is an open-air lounge on the 38th floor of Bangkok Marriott Marquis Queen's Park on Sukhumvit Soi 22, with skyline and sunset views and live DJs. Gin is the backbone: the bar holds more than 100 premium gins from around the world, poured as signature G&Ts and in cocktails. The signature list draws on Bangkok neighborhoods and landmarks, with drinks such as Boat Noodle, made with Hendrick's gin, galangal, coriander root and pandan, and Golden Mountain, with Monkey Shoulder and bamboo sticky rice tea. Akira Back's Japanese-Korean sharing plates cover the food. It is open daily from 5pm to 1am, walk-ins are welcome, and smart casual dress is recommended.
Above Eleven is a Peruvian rooftop bar and restaurant on the 33rd floor of Fraser Suites Sukhumvit, high above Sukhumvit Soi 11, and it has been running since 2012. The space is styled as an urban jungle, and the kitchen serves Nikkei food that joins Peruvian and Japanese cooking. Pisco drives the bar: the drinks menu has a full section of pisco sours, from the classic to mango and chili, alongside margaritas and house signatures such as Above the Clouds and the Kaizen. Resident DJs play nightly, and Wednesday is Salsa Night. It is open every day from 5pm to 2am, and the dress code bars sandals and flip-flops.
Alfresco 64 is the whisky bar on the 64th floor of State Tower on Silom Road, part of lebua, and it bills itself as the world's highest outdoor whisky bar. Inside, sleek nautical lines, lacquered rosewood floors and sunken seating are meant to evoke a yacht cabin, while the open-air terrace is shaped like a yacht's prow and juts out over the side of the building toward the river. The drinks list is built on whisky, from blended Scotch and single malts to Japanese bottles, and adds whisky cocktails such as Perihelion and a three-cocktail flight called The Amber Trilogy. Entry is for adults aged 20 and over, and walk-ins only.
Bar.Yard is the rooftop bar on the 40th floor of Kimpton Maa-Lai Bangkok on Soi Tonson, looking over Lumpini Park, with an air-conditioned indoor bar and an open-air terrace. The interiors use vivid colors and motifs such as the hornbill, the bird of paradise, the serpent and the sun. The cocktail list takes its cues from Thai culture: the BDSM is a spicy margarita with Altos Plata tequila, pomegranate and smoked chipotle, and Do You Dare mixes Acholado pisco and Campari with a bell pepper and raspberry cordial. A Zero Proof menu sits alongside. Peruvian chef Julio César Concha Muñoz runs a Pan-Latin and Thai kitchen, and happy hour runs daily from 5pm to 7pm.
These are the rooftop bars specifically. The full Bangkok guide ranks the best bars of every style, and the directory lists all 54 with a map and filters.