Weir was natural inside San Francisco, California and grew up in the suburban area of Atherton, California. He began swimming guitar at age long dozen fallowing less successful experimenting sustaining a piano & a cornet. He experienced pawithin in school because of undiagnosed dyslexia and was expelled from about each school he attended. He was sent away to Fountain Valley School in Colorado, where he was, predictably, asked to leave, but not prior to he befriended John Perry Barlow, who would be one of them independent lyrist for the Grateful Dead.

In New Year's Eve, 1963, 16-year-old Weir and another underage friend were wandering the back alleys of Palo Alto, looking for a club that would admit them, when they heard banjo music. It followed the music to its source, the music store, in which a immature Jerry Garcia, oblivious to the date, was waiting in his students to arrive. Weir & Garcithe spent a nighttime swimming music together and so decided to form a band. A band it formed was Mother McCree's Uptown Jug Champions, which became a Warlocks, and so a Grateful Dead.

In the Grateful Dead, he played rhythm & slide guitar and also split vocals by owning Jerry Garcia. Weir has the unique guitar style--his greatest influence is the stiff bop piano player McCoy Tyner. Shortly prior to Garcia's dying within 1995, Weir had formed a second band, a Ratdog Revue, late shortened to Ratdog. Weir likewise joined using more previous members of the Grateful Dead to tour when "The Other Ones", later renamed "The Dead."

Known for his rough, deeper tone, Weir sings covers by Bob Dylan, Chuck Berry and Johnny Cash while also performing numbers of of his have songs.

In July 15, 1999 he married Natascha Muenter. It keep around 2 girl, Shala Monet Weir & Chloe Kaelia Weir.