Belus Prajoux Nadjar (born 27 February 1955) is a retired professional tennis player from Chile.

Prajoux won six doubles titles on the ATP Tour during his career.

He reached a highest doubles ranking of No.

He was a member of the Chile Davis Cup team, and played on the team that reached the final of the 1976 Davis Cup.

Prajoux retired from the tour in 1986.