| Maciej Zajder | |
| Nationality: |  Polish |
| Birth Date: | 31 January 1988 |
| Birth Place: | Łask, Poland |
| Height: | 2.02 m |
| Weight: | 96 kg |
| Spike: | 345 cm |
| Block: | 325 cm |
| Position: | Middle blocker |
| Currentclub: | Stal Nysa |
| Currentnumber: | 1 |
| Years: | 2009–2011 2011–2013 2013–2014 2014–2016 2016–2017 2017–2018 2018– |
| Teams: | Siatkarz Wieluń AZS Politechnika Warszawska Trefl Gdańsk AZS Olsztyn Espadon Szczecin Warta Zawiercie Stal Nysa |
Maciej Zajder (born 31 January 1988) is a Polish volleyball player. At the professional club level, he plays for the Polish team, Stal Nysa, PlusLiga.
Zajder is an alumnus of Skra Bełchatów. From 2011 to 2013, he was a player of AZS Politechnika Warszawska.
In 2013 he won, a silver medal of the 2013 Summer Universiade held in Kazan.