A sinecure (from Latin sine = "without" and cura = "care") means an office that requires or involves little or no responsibility, labour, or active service. The term originated in the medieval church, where it signified a post without any responsibility for the "cure of souls", the regular liturgical and pastoral functions of a cleric, but came to be applied to any post, secular or ecclesiastical, that involved little or no actual work. Sinecures have historically provided a potent tool for governments or monarchs to distribute patronage, while recipients are able to store up titles and easy salaries.

A sinecure is not necessarily a figurehead, which generally requires active participation in government, albeit with a lack of power. A sinecure, by contrast, has no real day-to-day responsibilities, but may have de jure power.

A sinecure can also be given to an individual whose primary job is in another office, but requires a sinecure title to perform that job. For example, the Government House Leader in Canada is often given a sinecure ministry position so that he may become a member of the Cabinet. Similar examples are the Lord Privy Seal and the Chancellor of the Duchy of Lancaster in the British cabinet. Other sinecures operate as legal fictions, such as the British office of Crown Steward and Bailiff of the Chiltern Hundreds, used as a legal excuse for resigning from Parliament.