| Mait Klaassen | |
| Office1: | Minister of Education |
| Primeminister1: | Mart Siimann |
| Term Start1: | 17 March 1997 |
| Term End1: | 25 March 1999 |
| Predecessor1: | Rein Loik |
| Successor1: | Tõnis Lukas |
| Office2: | Rector of the Estonian University of Life Sciences |
| Term Start2: | 2008 |
| Predecessor2: | Alar Karis |
| Term Start3: | 1993 |
| Term End3: | 1998 |
| Predecessor3: | Olev Saveli |
| Successor3: | Henn Elmet |
| Birth Date: | 23 January 1955 |
| Birth Place: | Tartu, Estonia |
| Party: | Estonian Coalition Party |
| Alma Mater: | Estonian University of Life Sciences |
Mait Klaassen (born 23 January 1955 in Tartu) is an Estonian politician who served the Minister of Education from 17 March 1997, to 25 March 1999.
Klaassen was the rector of the Estonian University of Life Sciences 1993 until 1998, and again from 2008 until 2022. He has also been a member of the X Riigikogu and the XI Riigikogu.