James Riley Blake (born December 28, 1979 in Yonkers, New York, United States) is a professional tennis player and currently the second-highest ranked American, 23rd in the world (as of September 26, 2009). Blake is known for his speed and powerful, flat forehand. He reached the final of the 2006 Tennis Masters Cup but lost to World No. 1 Roger Federer in straight sets. On July 3, 2007, Blake's book, Breaking Back: How I Lost Everything and Won Back My Life, discussing his comeback after his unlucky 2004 season, was released and debuted at Number 22 on the New York Times Best Seller list. He wrote this book along with Andrew Friedman.

Blake was born in Yonkers, New York, United States to an African American father Thomas and a White British mother Betty. He has a brother, Thomas, who is also a professional tennis player, and three older half-brothers, Jason, Christopher, and Howard, and a half-sister, Michelle.

Blake started playing tennis at age five alongside his brother Thomas. When he was 13, he was diagnosed with severe scoliosis and for five years as a teenager, he was forced to wear a full-length back brace for 18 hours a day, though not while playing tennis. Blake attended Fairfield High School, in Fairfield, Connecticut, where a schoolmate and childhood friend was future musician John Mayer. Blake was inspired to pursue tennis after hearing his role model, Arthur Ashe, speak to the Harlem Junior Tennis Program. Brian Barker was his first (and longtime) coach. He left Harvard University after his sophomore year to pursue a career in professional tennis.