Peter MacNicol (born on April 10, 1954, in Dallas, Texas, USA) is an American actor. He has been married to Martha Sue Cumming since October 11, 1986. He portrays Simon Sifter in CBS's CSI:Cyber.


MacNicol began his career studying at the University of Dallas and University of Minnesota. While in Minnesota, he performed in two seasons at the Guthrie Theater. A New York talent agent spotted him and told him to make a move to Manhattan.


  • His wife, Marsue, runs a not-for-profit foundation that helps inner-city children in Los Angeles
  • Listed as one of twelve "Promising New actors of 1981" in John Willis' Screen World, Vol. 33.
  • He is best known as David Langley in Bean, John Cage in Ally McBeal, Dr. Larry Fleinhardt in Numb3rs and Jeff Kane in Veep.