Frank Jensen (born 28 May 1961) is a Danish politician, member of the Danish Social Democrats, and has been Lord Mayor of Copenhagen since 1 January 2010. He was Minister for Research 27 September 1994 to 30 December 1996 in the Cabinet of Poul Nyrup Rasmussen II and Justice Minister from 30 December 1996 to 27 November 2001 in the Cabinets of Poul Nyrup Rasmussen III and IV.
When Mogens Lykketoft resigned as leader of the Social Democrats after losing the 2005 Danish parliamentary election, Frank Jensen and Helle Thorning-Schmidt were the two candidates to succeed him. The party members voted on 12 April 2005, electing Helle Thorning-Schmidt as leader with 24,261 votes (53%) against 21,348 votes (47%) for Frank Jensen.
Frank Jensen is an educated economist and holds a master's degree in economics from Aalborg University which he received in 1986.
In May 2015, he banned all 45,000 city employees from flying with budget airline Ryanair for official business.