He previously played for the Canterbury-Bankstown Bulldogs, St. George Illawarra Dragons and Wests Tigers in the National Rugby League (NRL), and at representative level for the Prime Minister's XIII, World All Stars and Queensland in the State of Origin series.

[17][18] In round 8, he made his NRL debut for Canterbury against the Newcastle Knights, playing at centre replacing an injured Tim Lafai in the 16-12 win at ANZ Stadium.

[27][28][29] In Round 4 against the Wests Tigers, he kicked a field goal in golden-point extra time to win the match for Canterbury, 25-24.

at the End of the year Moses Mbye was offered a contract from Samoa but denied it cause he wanted no injuries during the preseason.

[citation needed] With the arrival of new coach Michael Maguire, Mbye was named Wests Tigers' captain in the pre-season.

"[40] Despite his club issues, Mbye played a starring role in Queensland Game 1 victory in 2019 State of Origin series.

[42][43][44] Mbye made a total of 15 appearances for the Wests Tigers in the 2020 NRL season which saw the club finish 11th on the table.

Mbye played a total of 22 matches for the Wests Tigers in the 2021 NRL season as the club finished 13th and missed the finals.

[46][47] In round 1 of the 2022 NRL season, Mbye made his club debut for St. George Illawarra in their 28-16 victory over the New Zealand Warriors scoring a try.

[49] On 24 July, it was announced that Mbye had signed a two-and-half-year deal to join English side St Helens with immediate effect.

[50] In round 21 of the 2024 Super League season, Mbye kicked the winning drop goal for St Helens in their 17-16 golden point extra-time victory over Salford.

[51] Mbye played 23 games for St Helens in the 2024 Super League season which saw the club finish sixth on the table.