The monument was conceived in 1939 as a temporary idea for the Portuguese World Exhibition in June 1940 by the architect José ngelo Cottinelli Telmo and the sculptor Leopoldo de Almeida. Under António de Oliveira Salazar's Estado Novo regime, the Monument to the Discoveries symbolised the romantic idealisation of Portuguese discovery. It was built in Praça do Império as a temporary construction as a part of an urban renewal initiative sponsored by Minister Duarte Pacheco, despite opposition from Cottinelli Telmo. However, the original building was destroyed after the exhibition in June 1943 as a result of the project's failure to materialise.

The government promoted the building of a permanent Monument to the Discoveries on February 3, 1958, under decree number 41-517, through the Ministry of Public Works, the Overseas Provinces, and the Municipal Chamber of Lisbon. The new monument was constructed between November 1958 and January 1960 using cement and pink stone from Leiria. The sculptures were created using limestone from the Sintra region. As part of the festivities to mark the 500th anniversary of the death of the Infante Henry the Navigator, the new project was greater in scale than the original 1940 model.

Although Cottinelli Telmo's designs served as the foundation for the project, he was eventually succeeded as the principal architect by António Pardal Monteiro, and stability studies were carried out under the supervision of engineers Edgar Cardoso, Ruy Correia, and António Franco e Abreu. António Pardal, who collaborated with Cristino da Silva to create the massive square, handled the interior design. Pardal finished the property's northern section, and José Raimundo finished the southern section. Leopoldo de Almeida modelled the sculptures using the likenesses of António Cândido and Carlos Escobar (under the guidance of António Branco and Alfredo Henriques), with the assistance of the artists Soares Branco and António Santos.

It was one of many national initiatives that tried to commemorate the Comemoraçes Henriquinas, celebrations honouring the anniversary of Henry the Navigator's passing, when it was inaugurated on August 9, 1960. The monument's maintenance was given to the General Administration of the Port of Lisbon, although it wasn't finished until 10 October of that year. Although the monument remained untouched between 1960 and 1979, an agreement to transfer ownership was reached with the Municipal Chamber of Lisbon in 1962. Although public works for the construction of a cultural centre, Centro Cultural das Descobertas, were not finished until 1985, when a public access to the highest part of the structure was inaugurated and an observation deck, an auditorium, and an exhibition hall were created, a document published in a municipal newspaper in November 1979 advanced the city's intentions to establish a permanent exhibition inside.

The public corporation Gesto de Equipamentos e Animaço Cultural received control of the Monument of the Discoveries in April 2003.