1929 Born in Stockholm to Sigrid Elisabeth Lindforss and Gösta Oldenburg, a diplomat attaché to the Swedish Consulate in New York.
1933 The Oldenburgs move to Oslo and remain there until 1936.
1936–45 They settle in Chicago, where Gösta served first as consul and later as consul general until his retirement in 1959.
1946–50 Claes Oldenburg graduates from the Latin School of Chicago and majors in English literature and art at Yale University.
1950–52 He takes night courses, and day courses later, at the Art Institute of Chicago, while working first as apprentice reporter for the City News Bureau.
1953 First public exhibition in a group show at the Club St. Elmo, Chicago.
1955 Leaves the Art Institute of Chicago; exhibits his drawings at 1020 Art Center. To support himself he works in the music department of a bookstore and as illustrator for Chicago magazine
1956 Oldenburg moves to New York.
1958 He meets Allan Kaprow and other artists associated to the Hansa Gallery at George Segal’s farm in New Brunswick.
1959 Tom Wesselmann and Marc Ratliff approach Oldenburg about a show in May at the basement of the Judson Memorial Church. Oldenburg starts his long-standing practice of collecting "Ray Guns."
1960 The series of performances Ray Gun Spex take including Oldenburg's 'Snapshots from the City' and his environment The Street place at the Judson Gallery. Marries Pat Muschinski (later Patty Mucha).
1961 At the end of this year the installation The Store opens for two months at a rented store on Manhattan’s East Second Street.
1962 From February to May, ten performances are held at The Store. During the summer, Oldenburg transforms the Store into a show at the Green He produces oversized soft canvas pieces as well as the plaster and enamel works produced for The Store studio.
1963 Oldenburg abandons New York attracted by the Los Angeles nascent scene. He works on the "environment" that will be present at the Sidney Jannis Gallery the following year, Bedroom Ensemble. He starts developing the theme of the Home.
1964 He returns to New York and is selected for a group show to represent the USA at the Venice Biennale. He travels through Italy and works in Paris for an exhibition held at the Galerie Ileana Sonnabend.
1965 Oldenburg creates the first drafts of the Museum of popular art, n.y.c. which will become the Mouse Museum later, and designs his first proposals for city monuments of enormous tridimensional objects
1966 The Moderna Museet presents his first major survey from 1963 to 1966. Oldenburg stages his final performance of the sixties, although later, in 1985, he creates “Il Corso del Coltello” in collaboration with Coosje van Bruggen, in Venice, Italy.
1969 The first "feasible" monument, Lipstick (Ascending) on Carterpillar Tracks, is commissioned by a group of Yale architecture students.
1972 The first building structure for the Mouse Museum is created for the Documenta 5, Kassel. Its exterior differs from the actual one created in 1977, in which the shape of the mouse is visible also from outside.
1975–76 He begins to collaborate with the art historian, sculptor, and critic Coosje van Bruggen in large scale projects for the public space. Over the following decades, they create important monuments which populate city landscapes and museum collections around the world.
1977 Marries Van Bruggen. The Mouse Museum in its actual exterior shape travels to different countries and venues.
1985 Oldenburg and Van Bruggen devise the performance Il Corso del Coltello with Germano Celant and Frank Gehry; for the performance Oldenburg and Van Bruggen create Knife Ship I, a large-scale motorized Swiss Army knife with oars to traverse Venice canals.
2009 Coosje van Bruggen passes away.
2012 The exhibition Claes Oldenburg: The Sixties opens at mumok, Vienna, followed by venues in Cologne, Bilbao, New York, and Minneapolis.