"Affliction" is the fifteenth episode of the fourth season of the American science fiction television series Star Trek: Enterprise, and originally aired on February 18, 2005. The script was written by Mike Sussman from a story by executive producer Manny Coto. It was the second episode of Enterprise to be directed by Michael Grossman. The episode is the first of a two-part story, which concludes with "Divergence".

The fourth season of the American science fiction television series Star Trek: Enterprise commenced airing on the UPN network in the United States on October 8, 2004 and concluded on May 13, 2005 after airing 22 episodes. Set in the 22nd century, the series follows the adventures of the first Starfleet starship Enterprise, registration NX-01. The fourth season saw changes made to the production team, with Manny Coto becoming the show runner. He had joined the team during the third season as a co-executive producer. Other changes included Star Trek novelists Judith and Garfield Reeves-Stevens being brought on board as writers.