Jonas was born in Teaneck, New Jersey, the son of Denise, a former sign language teacher and singer, and Paul Kevin Jonas, Sr., a songwriter, musician and former ordained minister at a Pentecostal Assemblies of God church.
As of July 1, 2009, he is engaged to longtime girlfriend Danielle Deleasa, a former hairdresser from New Jersey. To announce the engagement of Kevin and Danielle, Kevin's mother and father sent out the following email to members of the bands mailing list as well as posted the same message on the bands website and fan page.
"Our hearts are filled with joy today and we are happy to share with you that our son Kevin has asked Danielle Deleasa for her hand in marriage. Her answer was yes and it is such a blessing that she will be joining our family. Kevin and Danielle have not yet set a date. Family is very dear to us and we hope we have raised Kevin to be a wonderful man and husband. Please join us in our families celebration and in congratulating Kevin and Danielle. Thank you for all of your support."