The network announced the renewal on Twitter Thursday alongside a moving image of Schreiber with a Season 7 logo.
Ray Donovan follows the title character who is a professional fixer in Los Angeles who can make problems disappear.
Season 6, which will wrap-up on Jan. 13, has found Ray in New York. Production on Season 7 will take place in Spring 2019 in New York, Showtime said in a statement.
Eddie Marsan, Dash Mihok, Katherine Moennig, Pooch Hall, Kerris Dorsey, Devon Bagby and Graham Rogers also star on the series.