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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.