The twins were born in Gelnhausen, Germany to a father who is of Irish descent and an African-American mother. Their father was in the army when Tia and Tamera were born but later became a police officer. Their mother was also in the military and later managed their careers. They have two younger siblings, one of whom Tahj Mowry, is also an actor.

Tia and Tamera began entering pagents and talent shows while their family was stationed in Texas. At age twelve, they convinced their mother to move to California with them so they could pursue an acting career. She agreed, on the condition that they land an acting job the first month. In 1990, their family moved to California permanently and Tia and Tamera began appearing in commercials and other small roles.

They are best known for playing twins who were separated at birth and reunited as teenagers in the show Sister Sister. The series was developed for them after a producer spotted them on the set of Full House, a show on which their brother made regular appearances. Sister Sister was initially on ABC but was cancelled by the network after two years and picked up by the WB, where it ran for another four years. They also did voiceover work for the Disney cartoon series Detention.

After the show ended, both Tia and Tamera studied psychology at Pepperdine University. Both Tia and Tamera appeared in the movie The Hot Chick playing "ghettofied" cheerleaders, and Tamera's solo regular spot as Dr. Kayla Thornton on the Lifetime series Strong Medicine from 2004 until February 2006, when the show went off the air. Tia did voiceovers for the Bratz cartoon series as the voice of Sasha and has a few movie projects in the works.