John Doe and Jane Doe​ are accounts created by deceased ROBLOX co-founder Erik Cassel in 2004, although their join dates are listed as February 27, 2006. The name John Doe refers to an anonymous male, while Jane Doe refers to an anonymous female. John Doe's user ID is #2, while Jane Doe's user ID is #3.

During the very early phases of ROBLOX, both accounts were used by the administrators to accompany users playing ROBLOX. When somebody entered a game, the administrators would cease their current work and join that player's game. John Doe was last online on March 18, 2016 at 6:04 PM, while Jane Doe was last online December 4, 2015 at 2:39 PM. Before this, both accounts were last seen online February 27, 2006 at 3:06 PM (when ROBLOX officially left the alpha testing stage). Many ROBLOXians speculate that these accounts were accessed by password guessers.