Ryan was born on April 19, 1983 in New York. His mother, casting agent Mary Jo Slater, got him parts in several commercials and TV appearances in daytime soaps, along with his half-brother Christian Slater. In 1987, his brother Christian's fame was rising, so the family moved to Los Angeles. Ryan starred in many movies during the 1990s but has since quit acting to focus on his studies. He has been attending university in San Francisco since 2004 and has spent a lot of time in Japan, he has no plans to return to movies nor acting in general.


He uses the surname of his mother, Mary Jo Slater, and his half-brother, Christian Slater, rather than that of his father. Half-brother of actor Christian Slater. His father is his mother's 2nd husband, attorney William Henry Taron.