Lambert Doomer was a Dutch Golden Age landscape painter.

Doomer was the third of nine children of Herman Doomer (1595–1650) and his wife Baertje Martens, who ran a successful business in ebony-veneer furniture. Lambert was trained as a furniture maker like his father, but seemed to enjoy drawing more than woodworking and he became an artist. It is not known who trained him, but since his father supplied frames for Rembrandt, he probably had access to a teacher within his father's network. Rembrandt painted portraits of his parents for their 25th wedding anniversary, which was unusual at the time, in 1638.