The 1983–84 season was Sport Lisboa e Benfica's 80th season in existence and the club's 50th consecutive season in the top flight of Portuguese football, covering the period from 1 July 1983 to 30 June 1984. Benfica competed domestically in the Primeira Divisão, Taça de Portugal and the Supertaça Cândido de Oliveira, and participated in the European Cup after winning the previous league. They also played in the Iberian Cup with the La Liga winners, Athletic Bilbao.

In the second year of Eriksson at Benfica, he lost João Alves and Frederico Rosa but hired António Oliveira and Michael Manniche. Benfica started the season by winning the Portuguese Cup Final of the past season and the Iberian Cup. In the league, Benfica started strong until their drop points in October. A home win against Porto propelled them into first place, which they never lost. Twelve consecutive wins followed until they were stopped in February. In March, Benfica was knocked out of Europe and lost for the first time in the league. They reacted with five wins and a draw in the next month, before losing for a second time in late April. In May, Benfica confirmed their 26th league title, as Eriksson departed the club in June.

Benfica entered the new season having won the league, and reached the Portuguese Cup Final and the UEFA Cup Final. Due to conflict between Porto and the Portuguese Football Federation, the final for the Taça de Portugal did not took place and was postponed. During the transfer window, Benfica lost João Alves and Frederico Rosa, who opted not to renew their contracts. New signings included centre-back, António Oliveira and striker, Michael Manniche. The latter replaced Cláudio Adão, who stayed just one month in the club. The pre-season began on 17 July, with medical tests, followed by roughly two weeks of training sessions. Benfica made their presentation game to the fans on 31 July with Coventry City, and competed in North America, with Tecos and Toronto Blizzard. The pre-season closed with the Lisbon International Tournament, which they won. On 10 August, it was confirmed that the Portuguese Cup Final of the past season would be played on the 21, at Estádio das Antas. The first official game was the Iberian Cup with the La Liga winners, Athletic Bilbao. In a competition sponsored by the Portuguese Football Federation and the Royal Spanish Football Federation, that joined the Primeira Divisão and La Liga Champions in a two-legged Super cup.

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