Guido Marilungo (born 9 August 1989) is an Italian professional footballer who plays as a forward for Ternana.
Born in Montegranaro, the Province of Fermo, in the Marche region, he moved his first footsteps with his hometown club until the age of 14, when he was noted by FIFA agent Silvio Pagliari who proposed him to Sampdoria, which successively chose to sign the player and include him in their Giovanissimi Nazionali (under-15) squad for the 2003–04 season. He was pivotal in the 2007–08 Sampdoria under-20 double (Campionato Nazionale Primavera and Coppa Italia Primavera).
On 11 January 2009, he made his first team debut in a Serie A home league game as a second-half substitute against Palermo, a 2–0 loss for the Genoese club. Three months later, exactly on April 26, 2009, he made his first start in a 3–3 draw with Cagliari, with Marilungo scoring two goals, the first ones in his senior career.