Ryan Patrick O'Sullivan
- Bats Right, Throws Right
- Height 6' 2", Weight 190 lb.
- School San Diego State University, Oklahoma City University
- High School Valhalla High School
- Born September 5, 1990
Pitcher Ryan O'Sullivan has played in the minor leagues since 2011 (through 2014).
He was originally drafted by the San Francisco Giants in the 10th round of the 2008 amateur draft, one pick after utility player Chris Herrmann and ahead of pitcher Tommy Milone, but he opted not to sign. He did sign after being taken by the Los Angeles Dodgers in the 4th round of the 2011 amateur draft, with a bonus of $100,000.
After an unimpressive pro debut, O'Sullivan posted a 2.98 ERA in 2012. He began the year with the in the Dodgers system, but was sent to the Philadelphia Phillies as the player to be named later in a trade that netted the Dodgers pitcher Joe Blanton. His ERA in 2013 was 2.52 in 53 games for the Clearwater Threshers. He began 2014 with the Reading Fightin Phils.
His brother is pitcher Sean O'Sullivan.