Total System Services (commonly referred to as TSYS) is a United States credit card processor, merchant acquirer and bank credit card issuer. TSYS provides payment processing, merchant, and related payment services to financial and nonfinancial institutions in the United States, Europe, Canada, Mexico, and internationally. It operates through four segments: North America Services, International Services, Merchant Services, and NetSpend. TSYS is located in Columbus, Georgia, United States.

In 1959 TSYS started as a division of Columbus Bank and Trust (CB&T). In 1974, CB&T started processing credit cards for other banks. In 1983, TSYS became a separate publicly traded company, although majority ownership remained with CB&T and its successor, Synovus. In 1991, TSYS began development on the next generation of processing platforms. Then in 1994, TSYS launched TS2. On September 24, 1999 TSYS opened up its new Riverfront Campus in Downtown Columbus. On October 25, 2007, TSYS and Synovus (holding 81% of shares at the time) announced a spin-off that was completed as of the end of 2007.

In July 12, 1999, Total System Services, Inc. announced the signing of a multi-year agreement with Bancahsa, to process its Honducard-Visa credit cards, which represented a step in Total System Services' international expansion strategy to become the global processor of choice.

In 2004, following merger between Bank One and Chase to form J.P. Morgan Chase, TSYS was awarded a contract to process its credit services business of 87 million cards.

In 2008 TSYS launched n>genuity, a quarterly publication designed to provide pertinent research, in-depth commentary and timely insight on the trends that impact the world of payments

In 2010, TSYS announced they acquired majority stake in First National Bank of Omaha's merchant acquisition business for $150.5 million , which was renamed TSYS Merchant Solutions

In August 2012 TSYS announced a joint venture with Central Payments Co, one of the fastest growing ISOs in the US.

In November 2012 TSYS announced its acquisition of ProPay, a Utah-based company with over 250,000 merchants.

In February 2013 TSYS announced that it had agreed to purchase Netspend, a prepaid debit card provider, for $1.4 billion in cash.

In November 2013 TSYS announced TSYS Merchant Insights, a new partnership with Womply, a San Francisco-based startup, to provide revenue, social media, and reputation analysis tools to all TSYS merchants.

In February 2016 TSYS announced its agreement to acquire TransFirst in an all-cash transaction valued at $2.35 billion. The addition of TransFirst will make TSYS the sixth largest acquirer in the United States. The acquisition closed on April 1, 2016.

In February 2017, TSYS's lobbying of the GOP was credited for a bill that would remove the Consumer Financial Protection Bureau's limits on overdraft fees. 10-12% of NetSpend's revenue comes from these fees.