Mariah Copeland is a fictional character from the American soap opera, The Young and the Restless, portrayed by Camryn Grimes. Introduced by executive producer Jill Farren Phelps, the character made her first appearance on January 27, 2014. Grimes had previously played the role of Cassie Newman from 1997 to 2005, when the character was killed off. Mariah first appears in Genoa City, hired by Victor Newman to gaslight his former daughter-in-law Sharon Newman by posing as the ghost of Sharon's deceased daughter, Cassie, with whom she bears a remarkable resemblance. When the truth about her association with Victor is revealed, Sharon becomes drawn to a troubled Mariah, whom she moves into her home. Meanwhile, it is revealed that Mariah is the notorious ex-girlfriend of Tyler Michaelson; she is also linked to cult leader Ian Ward. While living with Sharon and Nick Newman, Cassie's adoptive father, Mariah develops an infatuation with Nick. It is soon discovered that Mariah is actually Cassie's twin sister and the daughter Sharon did not know she had. Her birth was kept secret, following Ian's arrangements for Mariah to be stolen at birth, and acted as a father figure to her for years. Mariah subsequently has relationships with Kevin Fisher—a dynamic which allowed Grimes to explore comic relief—and Devon Hamilton. She then develops feelings for her brother's girlfriend, Tessa Porter. Phelps described Mariah as a "loose cannon," while Grimes has characterized her as a "bad girl with a heart" and more dimensional than what viewers would expect her to be. Reaction to Grimes' return to the soap opera has been positive. Mariah's relationship with another woman proved controversial due to the soap opera's conservative audience, with TV Insider reporting that a gag order prevented Grimes from discussing it with the press. Nonetheless, the storyline also received positive reception and earned Grimes the Daytime Emmy Award for Outstanding Supporting Actress in a Drama Series in 2018, her second Daytime Emmy win.