Matheus Martinelli Lima (মাতেউস মার্তিনেলি), known as Matheus Martinelli or just Martinelli, is a Brazilian footballer who plays as a midfielder for Fluminense.

Born in Presidente Prudente, São Paulo, Martinelli started playing football at Marília, later playing for other clubs from the State of São Paulo before joining Fluminense in 2017.

Martinelli made his professional debut for Fluminense on 1 December 2020, starting in a 0–0 Série A draw against Red Bull Bragantino. He subsequently became a regular with the Tricolor, scoring 3 goals in 11 games and being named Série A man of the weekend on the 16 February 2021 after his performance against Ceará, scoring the second goal in his team 3–1 away win.