She began her career on the Off-Broadway stage before starring in the WGN America period drama series, Underground (2016–2017), for which she received NAACP Image Award nomination.
Vann appeared in secondary roles in films, including And So It Goes and Tracers, before her breakthrough performance as Ernestine, the head house slave of the Macon plantation, in the WGN America period drama series Underground in 2016.
In early 2018, Vann also went to star on the ABC drama pilot The Holmes Sisters produced by Regina King and Robin Roberts.
[13][14] Later that year, Vann also had a recurring role on the USA Network limited series Unsolved: The Murder of Tupac and The Notorious B.I.G.
In 2019, Vann was cast as corporate lobbyist Parker Campbell in season four of the OWN drama Queen Sugar.