A freelancer or (freelance worker) is a self-employed person working in a profession or trade in which full-time employment is also common. The word's etymology derives from the medieval term for a mercenary, a "free lance," which literally described a knight who was not attached to any particular lord, and could be hired for a given task.

A freelancer or freelance worker is a person who pursues a profession without a long-term commitment to any one employer.

Fields where freelancing is especially common include journalism and other forms of writing, computer programming and graphic design, consulting, and many other professional and creative services. The practice is widespread: for example, bounty hunters and mercenaries are freelancers, with their full-time counterparts being, respectively, the police and the military.

The Internet has opened up many freelance opportunities, expanding markets and helping to build it into one of the largest economic segments for many economies. Development for freelancing has been especially high for software development, information technology, and business documentation.

Freelance practice varies greatly. Some require clients to sign written contracts, while others may perform work based on verbal agreements, perhaps enforceable through the very nature of the work. Some freelancers may provide written estimates of work and request deposits from clients.

Payment for freelance work also varies greatly. Freelancers may charge by the day or hour, or on a per-project basis. Instead of a flat rate or fee, some consultants have adopted a value-based pricing method based on the perceived value of the results to the client. By custom, payment arrangements may be upfront, percentage upfront, or upon completion. For more complex projects, a contract may set a payment schedule based on milestones or outcomes.