Matthew D. Loeb is an American labor union leader.
Loeb joined the United Scenic Artists local of the International Alliance of Theatrical Stage Employees (IATSE) in 1989. In 1994, he began working for the union as an international representative, and chaired its East Coast Council for many years. He was later appointed as the union's first Division Director of Motion Picture and Television Production. In 2002, he was elected as a vice-president of the union, and then in 2008 as its president.
As leader of the union, Loeb led organizing drives, increased training and campaigned for improved safety. He was also elected as a vice-president of the AFL-CIO, to the executive of the UNI Global Union, and as president of its Media and Entertainment Industry sector.