Martin Michael Sellner[1] (born 8 January 1989) is an Austrian far-right political activist, and leader of the Identitarian Movement of Austria, which he cofounded in 2012.

[17] In 2006, at the age of 17, Sellner admitted to placing swastika stickers with another person on a synagogue in Baden bei Wien, Lower Austria.

Sellner did 100 hours of community service in a diversion at the Jewish cemetery in Baden, leading to the public prosecutor's office renouncing a criminal trial.

[19][20] In 2008, at the age of 19, he helped a leading Austrian neo-Nazi group hinder liberal demonstrations and made pilgrimages to memorial services for Wehrmacht soldiers.

[32][33] His computer, mobile phone, all data storage devices and cash cards were confiscated on suspicion that he was a member of a terrorist organization.

[37] Also in March 2019, U.S. authorities canceled his permit to travel without a visa to the United States according to Sellner, thus preventing him from visiting Pettibone, now his wife.

[42] In June 2019, Austrian police expanded their searches of Sellner's property in connection with the March 2019 Christchurch shootings by Brenton Tarrant.

According to the public prosecutor's office in Graz, inspection of Sellner's bank account was illegal for a lack of reasonable suspicion.

The Home Secretary, Sajid Javid, feared that Sellner might try to enter the UK again to train the local branch of Generation Identity and carry out public stunts that would promote "anti-Islamic and anti-immigration narratives".

[45] In 2023, Sellner proposed a plan to "remigrate" millions of people from Germany to North Africa at the 2023 Potsdam far-right meeting.

According to German public media, Sellner had stated on his Twitter account that he would be "pushed back and punished" if he tried to enter Germany during the ban.

[14] According to media reports, a senior police officer in Zurich had warned Sellner in a telephone call the day before that the intended event "must not take place".

[51] In 2017, Wolfgang Ullrich [de] suggested that there are connections between Sellner's worldview and the theories of the philosopher Martin Heidegger and the political theorist Carl Schmitt.

According to an interview of his from a 2017 documentary, Sellner's parents are understanding and supportive of his career, although they would have preferred him pursuing his studies in law and are concerned about possible politically-motivated attacks on him.