Roblox is an online game platform and game creation system developed by Roblox Corporation. It allows users to program games and play games created by other users. Created in 2004 and released in 2006, the platform hosts user-created games of multiple genres coded in the programming language Lua. For most of Roblox's history, it was relatively small, both as a platform and a company. Roblox began to grow rapidly in the second half of the 2010s, and this growth has been accelerated recently.

Roblox is free-to-play, with in-game purchases available through a virtual currency called "Robux". As of August 2020, Roblox had over 164 million monthly active users, with it being played by over half of all children aged under 16 in the United States.