[2][3] He was a one-year letterman in 2015 at Campbell University where he led the Fighting Camels in batting average (.340), runs scored (59), base hits (80), doubles (23) and triples (7).

[5] Mullins made his professional debut with the Low-A Aberdeen IronBirds in 2015, spending the whole season there, posting a .264 batting average with two home runs and 32 RBIs in 68 games.

[16] Mullins continued to struggle in Norfolk and was demoted to Double-A Bowie on July 10, though Orioles manager Brandon Hyde said the organization still felt "really highly about Cedric and his ability.

[20] He disclosed on February 2, 2022, that he was diagnosed with Crohn's disease,[21] and had 10 to 15 centimeters of intestine removed in November 2020 after playing the entire campaign with chronic abdominal pain.

[26] On September 24, Mullins became the first Orioles player to hit 30 home runs and steal 30 bases in a season since the franchise moved from St.

[29] On April 12, 2022, Mullins hit his first career grand slam off of Milwaukee Brewers starting pitcher Eric Lauer.

[30] Mullins was the seventh in Orioles history and second in two years following teammate Austin Hays to hit for the cycle in a 6–3 home victory over the Pittsburgh Pirates on May 12, 2023.

He singled in the third inning, tripled in the fifth, doubled in the seventh and hit a two-out three-run homer to right field off Duane Underwood Jr. in the eighth.

[31] Coming off the bench in the sixth inning of his third game after being activated from the injured list, he robbed Ty France of a potential game-tying solo homer in the ninth and hit a one-out two-run shot off Trent Thornton in the tenth of a 5–3 win over the Seattle Mariners at T-Mobile Park on August 13.

[33] His one-out three-run homer to right off Ryan Pressly in the ninth erased a two-run deficit and resulted in an 8–7 away win over the Houston Astros on September 18.