Oswin Appollis

Appollis started playing youth soccer with Island Rovers AFC in Bishop Lavis, Cape Town, at the age of nine. After he was initially placed in the B-team, he soon rose to the A-team. Appollis played on the school team at John Ramsay High School in Bishop Lavis and helped the school become the runners-up in the 2018 Kay Motsepe Schools' Championships.

SuperSport United

Appollis was contracted with SuperSport United before he was released.

University of Pretoria

Appollis was sent on loan to University of Pretoria, where he was reported to have scored two goals in 12 appearances for the National First Division club.

Pretoria Callies

After some months away from football, Appollis was recruited to the National First Division club Pretoria Callies by Kwanele Kopo, his former coach in the reserve league.

Polokwane City

Appollis featured for Polokwane City during the 2023–24 and 2024–25 season in the South African Premier Division.

Orlando Pirates

He joined Orlando Pirates at the start of the 2025–26 season for a reported transfer fee in the region of R16 million rand. Appollis scored a goal on his debut against his former club Polokwane City and won the penalty that led to the second goal in the match that ended 2–0.

Appollis made his debut for South Africa as a substitute for Sphephelo Sithole in the 75th minute in a loss to Rwanda on 21 November 2023 during 2026 FIFA World Cup qualification. His first two international goals for South Africa were scored against South Sudan during 2025 Africa Cup of Nations qualification. On 1 December 2025, Appollis was called up to the South Africa squad for the 2025 Africa Cup of Nations. He scored his fourth goal of 2025 against Angola at the 2025 Africa Cup of Nations. He was selected in South Africa's squad for the 2026 FIFA World Cup.

Appollis was born in Bishop Lavis, Cape Town, South Africa. His father is a gangster. He has credited his success to his grandmother, Maureen Appollis, who supported and motivated him for his career in football. Appollis enjoys playing video games such as FIFA and Call of Duty.