The 49-year-old actress and her writer-producer husband Kurt Sutter, 43, welcomed their first child together on Wednesday, Sagal's publicist Cara Tripicchio said.
Daughter Esme Louise Sutter was born via a surrogate in Los Angeles, Tripicchio said.
Sagal also has a 12-year-old daughter and a 10-year-old son from a previous marriage.
She rose to fame during the 1990s as big-haired, ditzy mom Peg Bundy on the hit Fox show.
Sutter's credits include the FX show, "The Shield."