| Competition: | Tercera División |
| Season: | 2005–06 |
| Dates: | August 2005–June 2006 |
| Matches: | 12920 |
| Prevseason: | 2004–05 |
| Nextseason: | 2006–07 |
During the 2005 - 06 season, the Tercera División - the fourth tier of professional football in Spain - consisted of eighteen regional groups.
See also: 2006 Tercera División play-offs.
| Key to colors in league table: | |
| Play-off for promotion | |
| Direct relegation |