Marlee Matlin married Kevin Grandalski, a police officer, on Aug. 29, 1993. According to Hands & Voices, Matlin met her husband on the set of Reasonable Doubts, an American police drama created by Robert Singer (via IMDb). "He's not Jewish, but I believe that we can share both our beliefs in a household together," Matlin said in a 2018 interview with Oregon Jewish Life. "We celebrate both holidays, and we were married by both a rabbi and a priest on the front lawn at Henry Winkler's house." The two dated for two years before tying the knot.

Matlin and Grandalski have four children: Sarah, Brandon, Tyler, and Isabelle. On Jan. 10, 2017, Matlin celebrated 30 years being sober and thanked her family via Twitter. "TODAY — 30 years of being sober (that's my chip)!" Matlin wrote. "I thank my husband, children, family, friends, and ME. I cannot imagine my life without it." In addition to thanking her family, Matlin also credited Betty Ford for helping her overcome her addiction (via People).

Also in 2017, Matlin ended the year celebrating her husband's career in the police force. She posted to Instagram a photo of the two with the caption, "Very proud wife of a retired police officer who just received his shadow box given by the Burbank Police Officers Association" with the hashtags #29.7years, #BPD, #policewife, #veryproud, #shadowbox, #myhusband, and #kevin.