This article contains episode summaries as well as directing and writing credits from Season 4 of the American drama/adventure television series Alias. Unlike all other seasons of the series, the fourth season aired entirely during the latter half of the American television season, from its season debut on January 5, 2005 (U.S.) to its season finale on May 25. The scheduling change allowed for a more continuous run.

This article contains episode summaries as well as directing and writing credits from Season 1 of the American drama/adventure television series Alias. Season 1 aired starting on September 30, 2001 (U.S.) and concluded on May 12, 2002.

This article contains episode summaries as well as directing and writing credits from Season 2 of the American drama/adventure television series Alias. Season 2 aired starting on September 29, 2002 and concluded on May 4, 2003.