Mary Nielsen Cook (born June 8, 1951) was a counselor in the general presidency of the Young Women organization of the Church of Jesus Christ of Latter-day Saints (LDS Church) from 2007 to 2013. She served as second counselor to Susan W. Tanner, with Elaine S. Dalton as first counselor, from March 2007 until April 2008. In April 2008, Dalton succeeded Tanner as Young Women General President and selected Cook as her first counselor. Cook has no biological children, but is the stepmother to Richard Cook's four children.