KeyBank is an American regional bank headquartered in Cleveland, Ohio, and the 27th largest bank in the United States. Organized under the publicly traded KeyCorp, KeyBank was formed from the 1994 merger of the Cleveland-based Society Corporation, which operated Society National Bank, and the Albany-headquartered KeyCorp. The company today operates nearly 1,000 branches and over 1,200 ATMs, mostly concentrated in the Midwest and Northeast United States, though also operates in the Pacific Northwest as well as in Alaska, Colorado, Texas and Utah.

KeyBank is the primary subsidiary of KeyCorp, which was formed in 1994 through the merger of Society Corporation of Cleveland, Ohio ("Society Bank") and KeyCorp ("Old KeyCorp") of Albany, New York. The merger briefly made Key the 10th largest US bank. Its roots trace back to the Commercial Bank of Albany in 1825 and Cleveland's Society for Savings, founded in 1849.^{[citation needed]}

Society For Savings originated in 1849 as a mutual savings bank, founded by Samuel H. Mather. In 1867, the modest but growing bank built Cleveland's first skyscraper, the 10-story Society for Savings Building on Public Square. Despite erecting the tallest structure between New York and Chicago at the time, the bank largely eschewed expansion. That aspect is highlighted by the fact that when it celebrated its 100th anniversary in 1949, it still only had one office although it had over $200 million (~$2.08 billion in 2024) in deposits. This conservatism helped the bank sidestep many depressions and financial panics. In 1958, Society converted from a mutual to a public company, which enabled it to grow quickly by acquiring 12 community banks between 1958 and 1978 under the banner Society National Bank.^{[citation needed]} It went through another growth spurt from 1979 to 1989, as it acquired dozens of small banks and completed four mergers worth one billion dollars, most notably Cleveland-based Central National Bank in 1986. In 1987, Society CEO Gordon E. Heffern retired and was succeeded by Robert W. Gillespie, who, although just 42, was a major figure and part of the office of the chairman for more than 5 years. Gillespie was also named chairman. Gillespie started as a teller with Society to earn money while he was finishing his graduate studies.

Society Corporation acquired Toledo, Ohio-based Trustcorp in 1990 and holding company AmeriTrust Corporation, in September 1991. Ameritrust was the successor to Cleveland Trust Company, which was Ohio's largest bank during the 1940s through the late 1970s. The AmeriTrust deal established Society as a large regional bank. However, its footing became unsteady due to bad real estate loans, forcing the resignation of AmeriTrust chairman Jerry V. Jarrett in 1990. Moreover, Gillespie was able to outbid Society's larger rival, National City Corp., which also bid for Cleveland Trust.

In 1825, New York Governor DeWitt Clinton signed a bill chartering the Commercial Bank of Albany. In 1865, Commercial Bank was reorganized under the National Banking Act of 1864, and changed its name to National Commercial Bank of Albany. Over a hundred years passed before National Commercial merged with First Trust and Deposit of Syracuse to become First Commercial Banks in 1971, still a modest New York State bank with 89 offices. Victor J. Riley Jr. became president and CEO in 1973, and changed First Commercial's name to Key Bank Inc. in 1979.

Riley embarked on a plan to grow Key through acquisitions. From the mid-1970s to the early 1980s, it made numerous acquisitions throughout upstate New York. Beginning in the 1980s, Riley looked outside New York, expanding Key's footprint with an acquisition in Maine, and eventually adding branches in Massachusetts and Vermont. However, by the mid-1980s, banking regulators in New England began looking askance at New York-based banks controlling the region's capital. That, coupled with increasing competition for acquisition targets, caused Riley to essentially abandon the Northeast. Instead, he began searching for prey in the Pacific Northwest. Riley found a target-rich environment in rural and underserved areas. He snapped up small banks in Wyoming, Idaho, Utah, Washington and Oregon. He even went so far as to buy two banks in Alaska, for which he was flogged in the media and in banking circles. Unorthodox strategy aside, Riley quintupled Key's assets from $3 billion to $15 billion in just four years between 1985 and 1990.^{[citation needed]}

While the early 1990s recession rocked many banks, Key had ample capital. It bought the assets of two failed thrifts from the government: Empire Federal Savings and Loan and Goldome Savings Bank. In March 1992, it acquired Tacoma-based Puget Sound Bancorp for $807.2 million (~$1.62 billion in 2024) to bolster its presence in Washington. Also in 1992, Key acquired Home Federal Savings of Fort Collins, its first move into Colorado. Key soon amassed nearly 700 banking offices.

The result was two separate banking networks united under a single corporate umbrella. However, this strategy actually worked well for Key. Not only was it insulated from regional economic downturns, but it avoided bad loans by lending primarily to customers in the areas it served. When Key acquired a bank, it retained most of the bank's personnel. Riley argued that a bank that entered new territory and "start(ed) shuffling people around" could not brand itself as a community bank.