Pearson was born in Baltimore Maryland, the daughter of two incarcerated drug addicts, and was raised in an East Baltimore foster home. Born a premature crack baby and weighing only three pounds, she was not expected to live. She was so small that she was fed with an eyedropper until she could be fed normally. According to her memoir, Grace After Midnight, she met her biological parents very few times; her mother was a crack addict and her father was an armed robber. She thus decided to go by her foster family's surname. She was a tomboy from a young age.
Pearson worked as a drug dealer. At the age of 14, she was convicted of second degree murder after the shooting of a girl named Okia Toomer, and was sentenced to two eight-year terms, to be served consecutively, at the Maryland Correctional Institution for Women in Jessup, Maryland. She was released after six and a half years.
Pearson said her life turned around at the age of 18 when Arnold Loney, a local drug dealer who looked out for her and sent her money in prison, was shot and killed. He was the one who gave her the nickname Snoop because she reminded him of Charlie Brown's beagle Snoopy in the comic strip Peanuts. While in prison, she earned her GED and was released in 2000. She landed a local job fabricating car bumpers, but was fired after only two weeks when her employer learned she had a prison record.
Pearson met Michael K. Williams, who played Omar Little on The Wire, in a Baltimore club. He invited her to come to the set one day. He introduced her to the writers and the producers, and after subsequent auditions, she was offered a role in the series. She has appeared in videos of R&B singer Lil' Mo's "Dem Boyz," rapper Rick Ross' "The Boss," "Here I Am," as well as "Cash Flow" by rapper Ace Hood and "Shabba (feat ASAP Rocky)" by A$AP Ferg..
For her performance in The Wire, Stephen King called her "perhaps the most terrifying female villain to ever appear in a television series".
In February 2015, Pearson appeared in Da Sweet Blood of Jesus as Lucky Mays.
In December 2015, Pearson appeared in Spike Lee's movie Chi-Raq as Dania.
In 2016, she played the role of Roxy Barnes in "Good Cop Bad Cop" the 2nd episode of the 7th season of the CBS police procedural drama Blue Bloods.
In 2016, Felicia also joined the cast of VH1's Love & Hip Hop: New York, a reality tv series which documents the personal lives, relationships and careers of individuals who have a history in the Hip Hop world.
Pearson was featured in the song "It's A Stick Up" with Tony Yayo and Mazaradi Fox. The music video for the song featured clips from The Wire. She has also discussed her plans for forthcoming musical projects in a number of interviews. She has the only speaking part in Snoop Dogg’s "So Many Pros," and appears in three "roles" in the video (a live-action montage of fake movie posters).
Pearson has also volunteered as a prison visitor and worked on anti-violence and literary campaigns for youths, and supported The Stay Strong Foundation.
On March 10, 2011, Pearson was arrested along with 60 others and charged with drug offenses. The arrest was made during a predawn raid at her home in Baltimore following a five-month DEA operation. Denying bail, Judge John Addison Howard, after Pearson expressed concerns about being recognized wherever she went, reasoned: "Well, you can change your appearance, I've seen the episodes of The Wire in which you appear. You look very different than you do here today, and I'm not talking about the jumpsuit, I'm talking about your general appearance." After a month in jail, Pearson was offered bail of $50,000 on April 8, 2011. In August 2011, she pleaded guilty to the charges a day before her trial was to begin. She was sentenced to a suspended seven-year prison term, with credit for time served, and given three years of supervised probation.