The couple's daughter Isabelle Amarachi Asomugha was born at about 5 p.m. on April 21 in Los Angeles, according to a birth certificate released Friday.
Washington's publicist said no statement was available.
Washington, 37, stars in the ABC series "Scandal." Asomugha, a former NFL cornerback for the Oakland Raiders, Philadelphia Eagles and San Francisco 49ers, announced his retirement last year.