This category lists modified vehicles in Grand Theft Auto Online, only available after upgrading their standard versions in Benny's Original Motor Works.

Custom vehicles were introduced in the Lowriders update for the enhanced version of the game, and have since being recurring in other DLCs; the Lowriders: Custom Classics update and the Import/Export update. The initial Lowriders release, along with the Custom Classics, are all eligible for hydraulics, while the Import/Export vehicles are not.

While most custom vehicles are denoted with a "Custom" name, 2 performance cars are simply named after their performance traits, those being the Banshee 900R and Sultan RS. Also, two retro-counterparts of existing sports cars are given a "Retro Custom" name.