A football helmet is a protective device used primarily in American football and Canadian football, the modern hard plastic version of which was created by Paul Brown. It consists of a hard plastic top with thick padding on the inside, a facemask made of one or more metal bars, and a chinstrap used to secure the helmet. Some players add polycarbonate visors to their helmets, which are used to protect eyes from glare and impacts. Helmets are a requirement at all levels of organized football, except for non-tackle variations such as flag football. Although they are protective, players can and do still suffer head injuries such as concussion. Each position has a different type of face mask to balance protection and visibility.

One of the first instances of football headgear dates to 1896 when Lafayette College halfback George "Rose" Barclay, began to use straps and earpieces to protect his ears. Many sources give credit for creation of the helmet to James Naismith, inventor of basketball. Additionally, other sources credit the invention of the football helmet to Navy Midshipmen football Joseph M. Reeves (later to become the "Father of Carrier Aviation"), who had a protective device for his head made out of mole skin to allow him to play in the 1893 Army-Navy game. Later helmets were made of padded leather, and resembled aviators' helmets. In professional football, at least, they were also optional. Some National Football League players, notably Hall-of-Famer Bill Hewitt, played all or most of their careers helmetless.

By the mid 1940s, helmets were finally required in the NFL. They were still made of leather, but with improved manufacturing techniques had assumed their more familiar spherical shape. By the 1950s, the introduction of polymers brought the leather helmet era to an end. The face mask was also introduced around this time, reducing the number of broken noses and teeth, but also necessitating new rules prohibiting opposing players from grabbing the face mask, a dangerous action which can call for a penalty of 5 or 15 yards, depending on severity and intention. The Los Angeles Rams were the first NFL team to put logos on their helmets, and as of 2008 only the Cleveland Browns do not have any form of primary logo on their helmets.

The helmet will sometimes be wrenched from a player's head in the jostling of a play and leave the player vulnerable to injury. Sports Illustrated for January 15, 2007, includes a couple of photos of Jeremy Shockey of the New York Giants, continuing to push for extra yardage in a playoff game against the Philadelphia Eagles, despite having lost his helmet during the play.

In 2007, Schutt Sports announced the arrival of a next generation helmet, the Schutt ION 4D. This next generation design was in response to the demand for a safer football helmet. The design includes an integrated faceguard. This new faceguard design features shock absorbing "Energy Wedges" that reduce the force of impacts to the faceguard. College Teams wearing the helmet include Air Force Academy, Penn State, and Virginia. Many of the New York Giants wear the ION 4D design including Amani Toomer and Brandon Jacobs.