P2istheName -- a popular YouTuber -- has died ... TMZ has learned.

The online star -- whose real name is Philip Enewally -- was found dead on Friday in a mailroom, according the Los Angeles County Coroner. Details are quite sparse at the moment -- but we know the coroner's investigation is ongoing.

TMZ spoke with a family member on Saturday ... and she confirmed he died Friday night and asked that everyone please respect the family's privacy as they grieve. She directed fans to his channel to mourn.

Fellow YouTuber COLETHEMAN shouted out his late friend after word spread ... posting about him on X and remembering he was always kind and provided content creation advice to help Cole improve his own videos.

P2istheName's last video was uploaded to YT about two weeks ago ... and, in a previous video, he said he planned to leave L.A. for Atlanta.

Enewally rose to prominence for posting NBA 2K and Fortnite gaming videos before moving to more general video game content, posting lots of "Let's Plays" -- walk-throughs of popular video games. He's since gone on to open up his own clothing line, WallyCo.

He gave his four million subscribers a look inside his life as well ... posting videos like this one -- where he showed them "a day in the life of a young black millionaire" in L.A.

Enewally was 26.

RIP