Catherine E. Coulson (October 22, 1943) is an American stage and screen actress who also works behind the scenes on various independent films. She is best known for her role as the Log Lady in the David Lynch TV series Twin Peaks.

Coulson met Lynch in the 1970s and performed various behind the scenes functions during the five year filming of his low budget classic Eraserhead (1977). She also appeared in Lynch's short film The Amputee (1974), in which she played a woman with no legs. During the filming of Eraserhead, Lynch told Coulson that he had an image in his head of her holding a large log. Fifteen years later, he created such a role for her in Twin Peaks, on which she guest starred for 12 episodes through seasons 1 and 2. Coulson went on to reprise her role in the film prequel, Twin Peaks: Fire Walk with Me.

Coulson was married to actor Jack Nance (who played Henry Spencer in Eraserhead, and Pete Martell in the Twin Peaks saga) in 1968, but they divorced in 1976. She is married to Rabbi Marc Sirinsky.