Nicolaos Matussis, Nicolae Matussi (Greek: Νικόλαος Ματούσης; 1898 – after 1981) was a Greek Aromanian lawyer, politician and leader of the Vlach "Roman Legion", an Italian-sponsored political and Aromanian paramilitary during World War II in Central Greece.
Nicolaos Matussis was born in Samarina in the Pindus mountains. He was a devoted Aromanian nationalist and from 1923 he was the general secretary of the Communist Party in Trikala. However in 1926 he was excluded by the party. Then he went to Larissa where he was active in Yannis Sofianopoulou's Rural Party. He practised law in Larissa before joining the Roman Legion that his compatriot, Alcibiades Diamandi, formed upon the onset of the Axis Occupation of Greece. In 1941 he was second in command of the so-called Roman Legion, an Italian-sponsored organization which assisted the Italian occupation forces, which Diamandi used in order to promote aromanian autonomy (and if allowed, a secessionist state - the Principality of the Pindus or "State of Pindus" or "Canton of Pindus") in north-western and central Greece. In 1942, after Diamandi suddenly left Greece to go to Romania, Matussi became leader of the so-called Roman Legion. Then, when the Legion collapsed since their Italian supporters left and were replaced by the Germans and the Greek resistance grew more active, he went to Athens, but he was obliged to flee to Romania like Diamandi the next year.
When the Axis collapsed and Romania was passed under Soviet influence, Matussi was sentenced in Communist Romania for 20 years in prison on a Danube island.