A staffing agency is a company that provides employees to work in another company on a temporary or permanent basis. Staffing agencies typically specialise in a particular industry or profession, and their primary purpose is to supply workers to companies that have an immediate need for extra staff but do not want to go through the process of recruiting and training new employees.

The use of staffing agencies has grown rapidly in recent years, as businesses have become increasingly temp-reliant. In the United States, the staffing industry employs nearly 4 million temporary and contract workers per day. And according to The Staffing Industry Analysts, the global staffing market is currently worth an estimated $415 billion.

While there are many different types of staffing agencies, the most common are generalist agencies, which provide labour for a variety of industries; industrial agencies, which place workers in manufacturing and production environments; IT agencies, which place workers with specific technical skills; healthcare agencies, which supply medical professionals such as nurses and therapists; and finally, government agencies, which help organisations fill both short-term vacancies and long-term jobs created by retirements or resignations within the public sector.

Generally speaking, when companies work with staffing agencies they are looking for two things: flexibility and cost savings. Flexibility because they only need to pay for the hours that their employees actually work (rather than sickness cover or holiday pay), and cost savings because they can access a pool of pre-vetted candidates who are ready to start working immediately (thus avoiding the time and expense of advertising positions internally).

Typically, when a business contacts a staffing agency they will firstly need to tell the agency what type of worker they are looking for (e.g. an accountant), as well as how long they need this person for (e.g. 3 months). The agency will then search its database of available candidates to find someone who meets these criteria and get in touch with them to see if they would be interested in taking on the role. Once both parties have agreed to proceed, the agency will arrange for the worker to start at the company on an agreed date/time .