Paychex, Inc. is a payroll and human resource service company which serves approximately 572,000 businesses in the US. The company is headquartered in Penfield, New York and has more than 100 locations across the country. The company provides services including Payroll Services, Time and Labor Management, HR Administration & Compliance, 401(k) Employee Benefits, Group Health Insurance, and Paychex HR Solutions.

Paychex was founded by Tom Golisano in 1971. Golisano started the company with $3,000 and the idea to make payroll outsourcing easy and affordable for small businesses. He saw an untapped market of American businesses with fewer than 100 employees, and went to his employer at the time, a regional payroll processor for big businesses, with his plan. The company wasn't interested, and Golisano started Paychex, employing only himself.

The operation grew to include 18 franchises and partnerships, which were eventually consolidated into one private company in 1979. In 1983, Paychex went public and began trading on The NASDAQ Stock Market. Since then, Paychex has registered a record of steady growth. In fiscal 2011, Paychex revenues exceeded $2 billion, as mentioned on their website.