After graduating in 1986, he worked as teaching assistant for constitutional law at his alma mater until 1988.

After returning to the Foreign Ministry in Vienna and a leave of absence to support the presidential campaign of Thomas Klestil, Martin Weiss was posted to the Austrian Embassy in Washington, D.C., where he held the positions of Political Counselor, Counselor for Congressional Affairs and Public Diplomacy, and later Director of the Austrian Press and Information Service.

He returned to Vienna in 2001 to take up the position of Director of the Press and Information Department at the Austrian Ministry of Foreign Affairs.

From 2004 to 2009 he served as Austrian consul general in Los Angeles, followed by his first ambassadorial posting as head of mission to Cyprus (2009-2012).

After returning once again to the Foreign Ministry in Vienna to lead the Press and Information Department from 2012 to 2015, Martin Weiss was appointed Austrian Ambassador to Israel in 2015, a position he held until 2019.