Header may refer to:

• Header (information technology), supplemental data at the beginning of a data block
• Header file, a text file used in computer programming (especially in C or C++)
• Page header, in printing or typography the material separated from the main body that appears at the top of a page
• An exhaust manifold in automotive engineering
• A headlong fall, particularly from a penny-farthing bicycle
• The commonplace name for the lintel structural member in building construction.
• Use of the player's head to direct the ball in association football (soccer)
• A competitor in the team roping rodeo event who specializes in roping a steer's head
• A herding dog with a specific method of interacting with its flock
• Header (film), a 2006 film
• the head of a combine harvester
• Header (soccer), act of hitting the ball with the head