Busson began dating American actress Uma Thurman in 2007 and they announced their engagement in June 2008. In December 2009, it was reported that the two had ended their engagement, but they reconciled and dated soon after their daughter's birth. Busson and Thurman have one daughter together, Rosalind Arusha Arkadina Altalune Florence Thurman-Busson, known as Luna (born July 2012 in Boston, MA). The couple called off the engagement for the second time in April 2014. In January 2017, Thurman and Busson began a custody battle to get custody of their daughter. Thurman ultimately received primary physical custody later that month.