Nantz was married to Ann-Lorraine "Lorrie" Carlsen Nantz for 26 years before divorcing in 2009. The couple lived in Westport, Connecticut, and had one child, daughter Caroline. In November 2009, Jim Nantz was ordered to pay his ex-wife $916,000 a year in child support and alimony. Nantz acknowledged dating a 29-year-old woman before the divorce was final, although the judge concluded the marriage deteriorated years earlier and "this remote event in no way contributed to the breakdown of the marriage." Nantz was said to earn $7 million in 2009.