A bistro or bistrot /ˈbiːstroʊ/, is, in its original Parisian incarnation, a small restaurant, serving moderately priced simple meals in a modest setting. Bistros are defined mostly by the foods they serve. French home-style cooking, and slow-cooked foods like cassoulet, a bean stew, are typical.

Bistros likely developed out of the basement kitchens of Parisian apartments where tenants paid for both room and board. Landlords could supplement their income by opening their kitchen to the paying public. Menus were built around foods that were simple, could be prepared in quantity and would keep over time. Wine and coffee were also served.

Today, bistros are mostly still part of the hospitality industry. They are often connected with hotels, bars, and pubs. They still often serve cheaper, simplified menus or menus that are not tied to a specific cultural cuisine.

The etymology is unclear, and is presumed to come from a regional word: bistraud, bistingo, bistouille, or bistrouille. The first recorded use of the word appears in 1884.  A popular folk etymology of the word claims that it originated among Russian troops who occupied Paris following the Napoleonic Wars (from быстро, "quickly"), which was allegedly shouted by Russian officers or Cossacks who wanted to be served quickly. This etymology has been discredited by some French linguists, as there is no attestation to the occurrence of this word until the end of the 19th century.