| Marcin Mastalerek | |
| Office: | Member of the Sejm |
| Constituency: | Sieradz |
| Term Start: | 8 November 2011 |
| Term End: | 11 November 2015 |
| Office1: | Chairman of Law and Justice Youth Forum |
| Term Start1: | 31 March 2011 |
| Term End1: | 4 July 2014 |
| Predecessor1: | Adam Hofman |
| Successor1: | Paweł Szefernaker |
| Party: | Law and Justice |
| Birth Date: | df=yes 15 September 1984 |
Marcin Mastalerek (born 15 September 1984) is a Polish politician of Law and Justice. Since 2023, he has served as chief of cabinet of the Chancellery of the President of the Republic of Poland.[1] He was previously a member of the Sejm from 2011 to 2015, and chairman of Law and Justice Youth Forum from 2011 to 2014.[2]