Patricia Burford Ryan (born August 9, 1954 in Las Cruces, New Mexico, United States) is an American writer of romance novels as Patricia Ryan, mystery novels as P.B. Ryan and erotica novels as Louisa Burton. She is the twin sister of the romance writer Pamela Burford. She won a Golden Heart award in 1994 in the category "short contemporary series" and a Romantic Times Reviewers’ Choice Award. Her book Silken Threads also won a RITA, the top award of the Romance Writers of America, for "Best Long Historical Romance" of 2000.