Automatic Data Processing, Inc. (ADP) is an American provider of human resources management software and services, headquartered in Roseland, New Jersey.

[4] It acquired the pioneering online computer services company Time Sharing Limited (TSL) in 1974 and Cyphernetics in 1975.

Lautenberg continued in his roles as chairman and CEO until elected to the United States Senate from New Jersey in 1982.

[5] From 1985 onward, ADP's annual revenues exceeded the $1 billion mark, with paychecks processed for about 20% of the U.S. workforce.

[8] In September 1998, ADP acquired UK-based Chessington Computer Centre that supplied administration services to the UK Government.

In January 2018, ADP acquired WorkMarket, a New York City–based software platform company that helps businesses manage freelancers, contractors, and consultants.

[29] BZ Results, winner of AutoSuccess magazine's 2005 "Innovative Company of the Year" award,[30] was purchased by ADP in 2006.