A music festival is a large event, usually held outdoors, which features numerous musicians or bands performing over a period of a few days. Many large festivals feature several stages, some showcasing a particular performance, and others providing alternatives to the acts playing on the main stage. Many music festivals have a specific genre of music associated with them, and others are classified by other factors such as nationality or ethnicity. Many outdoor music festivals offer camping facilities for attendees and generally have a range of food stalls, fairground games, and other attractions. Musicians perform at music festivals to give their fans a live show and attempt to gain new supporters.

The basic definition of a music festival is a large event with numerous musical acts performing over the course of one or more days. Many festivals take place over an entire weekend, with different acts performing on each day. Most festivals take place during the summer and are held outdoors, with stages erected across a large field or other open space. Smaller festivals will only have one stage, but larger ones can have three or more stages. Woodstock and Glastonbury are examples of well-known music festivals.

There is a specific genre of music associated with a music festival in most cases. For example, some festivals will focus specifically on pop, heavy metal, or indie music, and the attendees will usually have a strong interest in many artists within that genre. Most festivals publish the line-up of artists as soon as it is confirmed, to give prospective visitors an idea of what to expect. Festivals which take place over multiple days may have one day dedicated to one genre and the next day dedicated to another. A music festival which spans over multiple days will offer visitors the opportunity to attend just one day or the full festival.

Musicians like to perform at music festivals because it gives them a chance to perform in front of potential new fans. The variety of acts which perform at festivals means that some guests will only have one or two acts that they specifically want to watch on a given day. This means that many fans will watch musicians that they have not previously listened to, and possibly become fans of them. The acts may then increase album sales and garner support for future tours on the strength of an appearance at a music festival.

Some organizers start a music festival as a method of raising money for charity. The income from ticket and drink sales is shared amongst numerous charities or given to one specific charity at some events. Local businesses can also be used to help set up and run the event, generating more income for the local area.

If allowed, most guests will choose to camp over the entire course of the festival. Major festivals provide specific grounds for visitors to camp in, with various food and drink vendors nearby. Additionally, amenities such as showers and toilets are provided at most events. Attendees will need a tent in order to camp at a music festival, so many festivals will have camping shops on site with tents available to buy.