Federline was in a relationship with actress Shar Jackson. The couple have a daughter, Kori Madison Federline (born July 31, 2002), and a son, Kaleb Michael Jackson Federline (born July 20, 2004). Federline and Jackson separated shortly before the birth of their second child; during this time, Federline began dating pop singer Britney Spears. Jackson later commented that Federline's relationship with Spears "wasn't like just breaking up a relationship. It was like breaking up a family." Despite this statement, Jackson has sustained an amicable relationship with Federline. On January 12, 2007, Jackson stated, "He's a great dad and if you said his name right now, Kori would go crazy. That's the love of her life."

In July 2004, Federline and Spears announced their engagement, after three months of dating. The couple was married on September 18, 2004 in a surprise, non-denominational ceremony at a residence in Studio City, California, filing legal papers on October 6. The couple