He dated Taylor Swift for three months in 2008. Subsequently, he dated actress Ashley Greene from July 2010 until March 2011, then dated model Gigi Hadid in 2015. He began a relationship with Sophie Turner in 2016 and the two got married in 2019. He and Sophie welcomed a daughter named Willa together in July 2020. In July 2022, the couple welcomed their second child. Apart from Kevin and Nick, he has a third brother named Frankie. His parents are Denise Jonas and Paul Kevin Jonas Sr.
Taylor Swift wrote "Forever & Always," "Last Kiss" and "Better Than Revenge" after he broke up with her on the phone.