Hitchhiking (also known as thumbing, tramping, hitching, autostop or thumbing up a ride) is a means of transportation that is gained by asking people, usually strangers, for a ride in their automobile or other road vehicle to travel a distance that may either be short or long. The latter may require many rides from different people; a ride is usually, but not always, free. If the hitchhiker wishes to indicate that they need a ride, they may simply make a hand gesture (signs are also used). In North America and the UK, the gesture involves extending the hitchhiker's arm toward the road and sticking the thumb of their outstretched hand upward with the hand closed. In other parts of the world, it is more common to use a gesture where the index finger is pointed at the road. This cultural difference stems partly from an alternate offensive meaning for the thumbs up gesture in parts of Europe and Asia (see mention of Iran and Iraq in the article on Obscene gesture).

Hitchhiking, is a form of travelling, but the term may also refer to one of the following:

• "Hitch Hike" (song), a 1963 song by Marvin Gaye
• Hitch hike (dance), a dance move
• Hitchhike!, a 1974 made-for-TV movie starring Cloris Leachman
• Hitch-Hike (film), a 1977 crime film
• Genetic hitchhiking, the process by which an evolutionarily neutral or in some cases deleterious allele or mutation may spread through the gene pool by virtue of being linked to a beneficial mutation