Hessian (UK: /ˈhɛsiən/, US: /ˈhɛʃən/), burlap in North America, or crocus in Jamaica and the wider Caribbean, is a woven fabric made of vegetable fibres: usually the skin of the jute plant, or sisal leaves. It is generally used (in the crude tow form known as gunny) for rough handling, such as to make sacks in which to ship farm products and sandbags (although woven plastics now often serve these purposes), and for wrapping tree-root balls. However, this dense woven fabric, historically coarse, is also recently being produced in a more refined state—where it is known simply as jute—so as to provide an eco-friendly material for bags, rugs, and other products.

Hessian cloth comes in different types of construction, form, size and color. The name "hessian" is attributed to the historic use of this type of fabric as part of the uniform of soldiers from the former Landgraviate of Hesse (1264–1567) and its successors—such soldiers were called Hessians.

The origin of the word burlap is uncertain, though it appeared as early as the late 17th century. Its etymology is speculated to derive from the Middle English borel ('coarse cloth'), the Old French burel and/or the Dutch boeren ('coarse'), in the latter case perhaps interfused with boer ('peasant'). The second element is the Dutch word lap, meaning 'piece of cloth'.

Hessian was first exported from India in the early 19th century. It was traditionally used as backing for linoleum, rugs, and carpet.

In Jamaica and certain parts of the Caribbean (where it is known as crocus), enslaved Africans on the plantations were not generally given pleasant materials with which to make clothes. A lucky few had access to cotton that was spun, woven, cut and sewn into serviceable clothing (often called homespun), while others had to make do with whatever other materials they could find. Some repurposed discarded hessian sacks, fashioning their rough fabrics into garments that—although rough, itchy and uncomfortable—provided some protection from the heat and dust. A traditional costume of Jamaican Maroons uses fabric very similar to this material as a way of drawing an affinity and paying homage to the resourcefulness and creativity of their enslaved ancestors. For the rest of the population, it was used to make bags for carrying coffee beans and other items, edible or not.

Hessian is often used to make gunny sacks, and to ship goods like coffee beans and rooibos tea. It is breathable and so resists condensation and associated spoilage of contents. It is also durable enough to withstand rough handling in transit.

Its durability and handling when wet have also led to its use for temporary protection (as wet covering) to prevent rapid moisture loss during the setting phase of cement and concrete in the construction industry.

Hessian is also commonly used to make effective sandbags: hessian sacks filled with sand are often used for flood mitigation in temporary embankments against floodwaters, or in the building of temporary or field fortifications.