he ninth and final season of One Tree Hill, an American television series created by Mark Schwahn for The WB Television Network. The series was officially renewed by The CW for a ninth season on May 17, 2011; two days later, the network announced that the ninth season would serve as the series' final season. Premiering on January 11, 2012, the series aired its 13 episodes uninterrupted.
Series leads Bethany Joy Lenz and Sophia Bush continue as full-time regulars, while James Lafferty returned as a part-time regular. Paul Johansson and Tyler Hilton both return to the show for the final season as regulars, whilst former series regulars Chad Michael Murray, Antwon Tanner, Barbara Alyn Woods, and Craig Sheffer guest star.
The season opened to 1.75 million viewers and a 0.9 Adults 18-49 rating, up 26% in viewers vs. its season eight finale. The final episode aired on April 4, 2012, concluding the series with 1.43 million viewers.Overview from themoviedb.org