Haystacks is the common English title for a series of impressionist paintings by Claude Monet. The principal subject of each painting in the series is stacks of harvested wheat. The title refers primarily to a twenty-five canvas series which Monet began near the end of the summer of 1890 and continued through the following spring, though Monet also produced five earlier paintings using this same stack subject. A precursor to the series is the 1884 Haystack Near Giverny.

Impressionism was a 19th-century art movement characterized by relatively small, thin, yet visible brush strokes, open composition, emphasis on accurate depiction of light in its changing qualities, ordinary subject matter, unusual visual angles, and inclusion of movement as a crucial element of human perception and experience. Impressionism originated with a group of Paris-based artists whose independent exhibitions brought them to prominence during the 1870s and 1880s.