Martinus Hendricus Petrus "Martijn" van Dam (born 1 February, 1978) is a Dutch engineer and politician.

A member of the Labour Party (PvdA), he served as State Secretary for Economic Affairs from 3 November, 2015 until 1 September, 2017 in the Second Rutte cabinet.

He was active in different student associations and also joined the Young Socialists (Jonge Socialisten), eventually becoming the president of the Eindhoven chapter.

Following the 2006 elections he became spokesman for foreign affairs, which made him the face of the Labour Party in the debate on the extension of the military mission in Uruzgan.

In November 2015 Van Dam became State Secretary for Economic Affairs, succeeding Sharon Dijksma, who moved to the Ministry for Infrastructure and the Environment.