From 1979 to 1997, Fandi made 101 appearances for the Singapore national football team, scored 55 goals and earned a place in the Asian Football Confederation Hall of Fame. He started as captain of the national youth team that won the Lion City Cup in 1976 and 1977, then joined the senior national team on a tour of Russia, where he played in two friendly games and scored two goals in the second. His first senior cap came at 17 years, 3 months and 23 days, making him Singapore's youngest-ever full international, until his record was broken by Hariss Harun in 2007. However, in his first international competition, the 1979 SEA Games, Fandi did not score in four matches. He scored against India and North Korea in the Olympic Games qualifiers, but did not score in three FIFA World Cup qualifying matches. In the 1981 Ovaltine Cup, Fandi scored all Singapore goals in the 3–2 aggregate victory over Malaysia. Fandi scored a goal in a 1–2 loss to Thailand in the 1981 King's Cup and a hat-trick against the Philippines at the 1981 SEA Games. In 1992, Fandi scored twice against Nepal and once against Thailand in the King's Cup, then scored when Singapore beat Malaysia 3–1 in the Ovaltine Cup.