He previously played for the Newcastle Knights in the NRL, and Huddersfield Giants, Warrington Wolves and Castleford Tigers in the Super League.

[5] He played his junior rugby league for the Ourimbah Wyoming Magpies, St Edwards Bears and The Entrance Tigers, before being signed by the Newcastle Knights.

[21] He finished the tournament as equal top try-scorer with 4 tries alongside Solomone Kata, Jack Bird, Justin O'Neill, Bryson Goodwin and Matt King.

[25] On 27 September, he played at fullback in the Knights' 2015 New South Wales Cup Grand Final win over the Wyong Roos.

[citation needed] Mamo made his first appearance for the Warrington Wolves in the Ryan Atkins testimonial game against the Widnes Vikings, scoring a hat-trick in the process He played in the 2019 Challenge Cup Final victory over St. Helens at Wembley Stadium.

[35] Mamo played ten games for Warrington in the 2020 Super League season as the club qualified for the playoffs but were eliminated in the first week by Hull F.C.

[citation needed] In round 8 of the 2021 Super League season, Mamo scored two tries for Warrington in a 62-18 victory over Salford.

[38] Mamo was given squad number 4 for Castleford, and made his first appearance for the club on 11 February against the Salford Red Devils.

[41] On 15 March, Castleford Tigers announced that Mamo had left the squad with immediate effect, and this was later confirmed to be due to a back injury.