Heerenveen St. Juste started his career for SV Marum. In summer 2007 he joined to
Jong Heerenveen. He made his
Eredivisie debut on 24 January 2015 against
Vitesse. He replaced
Joost van Aken in injury time in a 4–1 home win. On 16 January 2016, he scored first Eredivisie goal in a 5–2 away defeat against
Zwolle.
Feyenoord St. Juste moved to
Feyenoord on 18 July 2017 on a four-year deal. He made his debut for that club on 9 September 2017 in a match against
Heracles Almelo. Later that year, on 17 December, he scored his first goal in a 7–0 away victory over
Sparta Rotterdam in the
Rotterdam derby.
Mainz 05 On 7 August 2019, Feyenoord announced on their website St. Juste was moving to
Mainz on a four-year contract for an undisclosed fee. A month later, on 14 September, he scored his inaugural
Bundesliga goal in the 88th minute of a 2–1 victory over
Hertha BSC.
Sporting CP On 11 May 2022, it was confirmed that St. Juste would sign for Portuguese club
Sporting CP at the beginning of the
2022–23 season. The deal was worth a reported €9.5 million. Later that year, on 2 September, he scored his first
Primeira Liga goal in a 2–0 away win over
Estoril. The next season, St. Juste had rumors of interest from
Liverpool F.C. after becoming a frequent starter for
Ruben Amorim. In the
2024 Taça de Portugal final, he scored the first goal for his club against
FC Porto, before being sent off in the first half, in a match which ended in a 2–1 defeat after extra time. At the start of the
2025–26 season, after being considered surplus to requirements by manager
Rui Borges and allegedly rejecting arranged transfers to
Osasuna and
Union Berlin, St. Juste was relegated to Sporting's
B team.
Return to Feyenoord On 22 January 2026, St. Juste left Sporting CP and returned to Feyenoord on a free transfer, signing a contract until June 2027, with an option for a further year. ==International career==