A Matter of Time (Italian: Nina) is a 1976 musical fantasy film directed by Vincente Minnelli and starring Liza Minnelli, Ingrid Bergman and Charles Boyer. It features songs by the duo of Kander and Ebb, George Gershwin, and B.G. DeSylva. The screenplay, written by John Gay, is based on the novel The Film of Memory (La Volupté d'être) by Maurice Druon.

The fictional story is based loosely on the real life exploits of the infamous Italian eccentric, the Marchesa Casati, whom Druon knew during her declining years in London while he was stationed there during World War II.

An American-Italian co-production, A Matter of Time had a troubled production, which led an aging Vincente Minnelli to be removed from creative control during post-production. The film marked the first screen appearance for Isabella Rossellini, the last for Charles Boyer and Amedeo Nazzari, and it proved to be Minnelli's final project.