Justin Greaves is a versatile right-handed batting all-rounder with and experience of playing for both Barbados and the Combined Campuses and Colleges in West Indian domestic circuit. He represented West Indies Under-19 team at the 2012 Under-19 World Cup in Australia.

Greaves showcased his cricketing prowess in England, playing for Sefton Park CC in the Liverpool and District Cricket Competition in 2013. His remarkable debut included scoring 109 and taking 4–32 against Old Xaverians. During the season, he accumulated 742 runs at an impressive average and claimed 31 wickets in 18 league games, contributing significantly to Sefton's triumph in the second division.

Making his debut for Barbados in January 2016 against ICC Americas in the 2015–16 Regional Super50, Greaves continued to make strides in his career. He ventured into T20 cricket, playing for the Barbados Tridents in the 2019 Caribbean Premier League and later earning a spot in the West Indies Emerging Team for the 2019–20 Regional Super50.

In June 2018, he was selected in the Cricket West Indies B Team squad for the inaugural Global T20 Canada tournament. His all-round abilities and adaptability were further recognized when he made his One Day International (ODI) debut for West Indies against Ireland on 8 January 2022, after being named in the squad for the series against Pakistan.

Known for his utility as an all-rounder, Justin Greaves earned a place in the West Indies squad for the series against Australia in January 2024, further cementing his continued contribution to West Indies cricket. His rise continued when he scored his maiden Test century in November 2024, making a brilliant and unbeaten 115 against Bangladesh in Antigua.