Dorothy Marie Mengering (née Hofert, formerly Letterman; July 18, 1921 – April 11, 2017), better known to Late Night and Late Show viewers as Dave's Mom, was the mother of late-night talk show host David Letterman and frequent telephone and live guest on his show. She appeared on camera (identified as Dorothy Mengering) on Late Night with David Letterman on the "Parents' Night" broadcast of February 25, 1986, in which the parents of many Late Night staffers were also seen. Following several years of appearing via telephone, Mengering (usually billed as "Dave's Mom" or "Dave's Mom Dorothy", with no mention of her surname) became a recurring on-camera guest on Letterman's subsequent Late Show, initially by covering the 1994 Winter Olympics in Lillehammer, Norway. She lived in Carmel, Indiana, at the time of her death. Personal life Dorothy Mengering was born Dorothy Marie Hofert in Linton, Indiana, the oldest child of Lena M. (née Strietelmeier) and Earl Jacob Hofert. Mengering's maternal grandparents, Fredricke Hilgediek and William Strietelmeier, were born in Germany, and her father was of German descent. A younger brother, Earl Jr. (1922–2009), and sister, Hazel (1923–2017) who died at age 93, less than three months after Mengering, were born respectively. Dorothy's first cousin is the grandmother of the model and actress Rebecca Romijn, a fact which was discussed on the Late Show with David Letterman. Mengering spent a year at Indiana University before marrying Harry Joseph (Joe) Letterman in 1942, with whom she had three children: Jan, David, and Gretchen. While raising her children, she assisted her husband, a florist, and worked as a secretary at her church, Second Presbyterian; she was widowed in 1973. In 1983, she married again, this time to Hans Mengering, a retired engineer and decorated World War II veteran who died on March 12, 2013. Appearances on Late Night Mengering made her first (and only) in-person appearance on Late Night as part of the "Parents' Day" broadcast of February 25, 1986. As part of the broadcast, Letterman cajoled her into yelling out the production office window with a bullhorn. Beginning in June 1990, Letterman would occasionally call his mother at home during the show. Mengering, who always addressed her son as "David", would patiently answer her son's questions and generally play along with his suggestions—though some of Letterman's more deliberately nonsensical suggestions were kindly but firmly shut down. Letterman's phone calls would usually involve