Denis Richard McDonough (born December 2, 1969) is an American government official serving as the 11th United States Secretary of Veterans Affairs under President Joe Biden since 2021. McDonough served in the Obama Administration as chief of staff at the National Security Council from 2009 to 2010 and as Deputy National Security Advisor from 2010 to 2013.

He also served as White House Chief of Staff for the full second term of President Barack Obama from 2013 to 2017. He was the second-longest Democrat to serve as the chief of staff since John R. Steelman in 1946, and the longest since Andrew Card (5 years, 84 days) during the first and second terms of the Bush administration.