Montjuïc is translated as Hill of the Jews in the medieval Catalan language, or as a corruption of Latin Mons Jovicus (that is, hill of Jupiter). The name is found in several locations in the Catalan Countries: the Catalan cities of Girona and Barcelona have a Montjuïc, as does the island of Minorca. When written in a Spanish (Castillian) rather than Catalan context it is generally spelled Montjuich (in the old Catalan spelling before Pompeu Fabra's orthography).

Barcelona's Montjuïc is a broad shallow hill with a relatively flat top overlooking the harbour, to the southeast of the city center. The eastern side of the hill is almost a sheer cliff, giving it a commanding view over the city's harbour immediately below. The top of the hill (a height of 173 metres) was the site of several fortifications, the latest of which (the Castell de Montjuïc) remains today. The fortress largely dates from the 17th century, with 18th century additions. In 1842 the garrison (loyal to the Madrid government) shelled parts of the city following disturbances. It served as a prison, often holding political prisoners, until the time of General Franco. The castle was the site of numerous executions. In 1897 an incident popularly known as Els processos de Montjuïc prompted the execution of anarchist supporters, which in turn lead to a severe repression of the workers' struggle for their rights. On different occasions during the Spanish Civil War, both Nationalists and Republicans were executed there, each at the time when the site was held by their opponents. The Catalan nationalist leader Lluís Companys i Jover was also executed there in 1940, having been extradited to the Franco government by the Nazis.

Naturally wooded, the slopes of the Montjuïc were traditionally used to grow food and graze animals by the people of the neighboring Ciutat Vella. In the 1890s the forests were partially cleared, opening space for parklands. The site was selected to host the 1929 International Exposition (a World's Fair), for which the first large-scale construction on the hill was begun. The surviving buildings from this effort include the grand Palau Nacional, the Estadi Olímpic (the Olympic stadium), the ornate Font Màgica fountains, and a grand staircase leading up from the foot of the Montjuïc at the south end of the Avenida de la Reina Maria Cristina, past the Font Màgica and through the Plaça del Marquès de Foronda and the Plaça de les Cascades to the Palau Nacional. The Poble Espanyol, a "Spanish village" of different buildings built in different styles of Spanish architecture, also survives, located on the western side of the hill. Mies van der Rohe's German national pavilion was constructed at the foot of the hill, near the Plaça del Marquès de Foronda. It was demolished in 1930 but was rebuilt in 1988.

Also completed in 1929, the Olympic stadium was intended to host an anti-fascist alternative Olympics in 1936, in opposition to the 1936 Berlin Olympics. These plans were cancelled due to the outbreak of the Spanish Civil War. The stadium serves as the home for football team Espanyol.

The roads in the slopes facing the city were once the Montjuïc circuit Formula One racing circuit, hosting the Spanish Grand Prix on four occasions. However, a terrible accident in the 1975 race saw Rolf Stommelen's car crash into the stands, killing four people; as a result the Spanish Grand Prix never returned to Montjuïc circuit.

The Montjuïc was selected as the site for several of the venues of the 1992 Summer Olympics, centered around the Olympic stadium. Extensively refurbished and renamed the Estadi Olímpic Lluís Companys, the 65,000-seat stadium saw the opening and closing ceremonies and hosted many events. Around it was build the Anella Olímpica (the "Olympic Ring") of sporting venues, including the Institut Nacional d'Educació Física de Catalunya (a center of sports science), the Piscines Bernat Picornell (the venue for swimming and diving events), and the striking telecommunications tower, designed by the architect Santiago Calatrava.

The ornate Palau Nacional houses the Museu Nacional d'Art de Catalunya, an extensive showcase of Catalan painting and sculpture.

The top can be reached using a funicular (part of the Barcelona Metro) and then a cableway. Part of the slopes are covered with a well attended park and gardens. The hill is often used for amateur cycling.

Also on the Montjuïc: a) Fundació Joan Miró, a modern art museum centering around a large collection of the works of Joan Miró, b) Cementiri del Sud-Oest, a cemetery containing many of Barcelona's rich and celebrated, including Lluís Companys and his predescessor as President of Catalonia Francesc Macià, as well as artist Joan Miró, dancer Carmen Amaya and poet/priest Jacint Verdaguer. Numerous unmarked graves hold those executed in the fortress, c) The botanic gardens, d) The museum of ethnology, e) The Catalan museum of archaeology (housed in the 1929 exhibition's palace of graphic arts).