Mario Merz (1 January 1925 – 9 November 2003) was an Italian artist, and husband of Marisa Merz.

Born in Milano, Merz started drawing during World War II, when he was imprisoned for his activities with the Giustizia e Libertà antifascist group. He experimented with a continuous graphic stroke–not removing his pencil point from the paper. He explored the relationship between nature and the subject, until he had his first exhibitions in the intellectually incendiary context of Turin in the 1950s, a cultural climate fed by such writers as Cesare Pavese, Elio Vittorini, and Ezra Pound.

He met Marisa Merz during his studies in Turin in the 1950s. They were associated with the development of Arte Povera, and they were both influenced by each other’s works.