Poster for a Dada exhibition at Sidney Janis Gallery

Sidney Janis was an American art dealer and collector whose gallery in New York became instrumental in presenting European modernism and early American abstraction to postwar audiences. Active as a dealer from the 1940s onward, Janis represented artists including Willem de Kooning, Jackson Pollock, and Mark Rothko, and later championed Pop Art and Minimalism. His eye for emerging movements shaped the institutional recognition of Abstract Expressionism in particular.