 
     
        Sydney Bristow discovers that her employers at SD‑6 are actually enemies of the CIA, forcing her into a dangerous double life. As she secretly reports to the real CIA, she confronts betrayal—including from her fiancé and possibly even her father—while infiltrating missions that uncover her family’s deep ties to conspiracy.
| Name | First Aired | Runtime | Image | |
|---|---|---|---|---|
| S01E01 | Truth Be Told | September 30, 2001 ABC (US) | 64 | |
| S01E02 | So It Begins | October 7, 2001 ABC (US) | 44 | |
| S01E03 | Parity | October 14, 2001 ABC (US) | 41 | |
| S01E04 | A Broken Heart | October 21, 2001 ABC (US) | 43 | |
| S01E05 | Doppelgänger | October 28, 2001 ABC (US) | 43 | |
| S01E06 | Reckoning | November 18, 2001 ABC (US) | 43 | |
| S01E07 | Color Blind | November 25, 2001 ABC (US) | 43 | |
| S01E08 | Time Will Tell | December 2, 2001 ABC (US) | 43 | |
| S01E09 | Mea Culpa | December 9, 2001 ABC (US) | 44 | |
| S01E10 | Spirit | December 16, 2001 ABC (US) | 43 | |
| S01E11 | The Confession | January 6, 2002 ABC (US) | 43 | |
| S01E12 | The Box (1) | January 20, 2002 ABC (US) | 44 | |
| S01E13 | The Box (2) | February 10, 2002 ABC (US) | 44 | |
| S01E14 | The Coup | February 24, 2002 ABC (US) | 44 | |
| S01E15 | Page 47 | March 3, 2002 ABC (US) | 44 | |
| S01E16 | The Prophecy | March 10, 2002 ABC (US) | 43 | |
| S01E17 | Q&A | March 17, 2002 ABC (US) | 43 | |
| S01E18 | Masquerade | April 7, 2002 ABC (US) | 44 | |
| S01E19 | Snowman | April 14, 2002 ABC (US) | 43 | |
| S01E20 | The Solution | April 21, 2002 ABC (US) | 43 | |
| S01E21 | Rendezvous | May 5, 2002 ABC (US) | 44 | |
| S01E22 | Almost Thirty Years season finale | May 12, 2002 ABC (US) | 44 |