| Doctor Who | |
|---|---|
| Season 21 | |
 Cover art of the Region 2 DVD release for first serial of the season | |
| Starring | |
| No. of stories | 7 |
| No. of episodes | 24 |
| Release | |
| Original network | BBC1 |
| Original release | 5 January – 30 March 1984 |
| Season chronology | |
The twenty-first season of British science fiction television series Doctor Who began on 5 January 1984 with the Fifth Doctor (Peter Davison) serial Warriors of the Deep, and ended on 30 March 1984 with Colin Baker's first serial The Twin Dilemma. For the third time (the first being during Season 4 and second being Season 18), the entire TARDIS crew changed over the course of a single season. John Nathan-Turner produced the series, with Eric Saward script editing.