The 1998–99 European football season was the 95th season of Sport Lisboa e Benfica's existence and the club's 65th consecutive season in the top flight of Portuguese football. The season ran from 1 July 1998 to 30 June 1999; Benfica competed domestically in the Primeira Divisão and the Taça de Portugal. The club also participated in the UEFA Champions League as a result of finishing second in the Primeira Divisão in the previous season.