The 37-year-old was shot in the head near MacArthur Boulevard and 94th Avenue around 8 p.m.
Officers say he was transported to a local hospital, where he was pronounced dead.
Oakland police are investigating but had not identified any suspects or made any arrests as of Tuesday afternoon.
Meanwhile, fans have been gathering in Oakland to pay their tribute.
Many are also offering their condolences on social media.
The Jacka was active in the Bay Area rap scene since 1999, when he released his first album with the group Mob Figaz. The group sold 160,000 copies of the album.
He self-published a solo album in 2001 and released more than a dozen albums and mixtapes since. Throughout his career, he collaborated with numerous influential Bay Area artists, including E-40, Andre Nickatina,
Yukmouth, Messy Marv and Keak Da Sneak.
PHOTOS: 2015 famous deaths