• Birthplace: Connecticut, USA
• Age: 36
• Height: 167
• Weight: 0
• Website: N/A

Allison Howell Williams, born April 13, 1988, is an American actress, comedian, and singer. She is best known for her role as "Marnie Michaels" on the HBO comedy-drama series, Girls (2012). Williams was born and raised in New Canaan, Connecticut, and is the daughter of former NBC Nightly News anchor and managing editor, Brian Williams, and Jane Gillan Stoddard, a TV producer. She graduated from Yale University in 2010.