Chemical Bank, headquartered in New York City, was the principal operating subsidiary of Chemical Banking Corporation, a bank holding company. In 1996, it acquired Chase Bank, adopted the Chase name, and became the largest bank in the United States. Prior to the 1996 merger, Chemical was the third-largest bank in the U.S., with $182.9 billion in assets and more than 39,000 employees. In addition to operations in the U.S., it had a major presence in Japan, Germany, and the United Kingdom. It was active in both corporate banking as well as retail banking as well as investment banking and underwriting corporate bonds and equity.

The bank was founded in 1824 as a subsidiary of the New York Chemical Manufacturing Company by Balthazar P. Melick and others; the manufacturing operations were sold by 1851. Major acquisitions by the bank included Corn Exchange Bank in 1954, Texas Commerce Bank in 1987, and Manufacturers Hanover in 1991. The bank converted to the holding company format in 1968.

Before its 1996 merger with Chase, Chemical had two operating segments: the Global Bank and Consumer & Relationship Banking.

In 1823, the New York Chemical Manufacturing Company was founded by Balthazar P. Melick and directors John C. Morrison, Mark Spenser, Gerardus Post, James Jenkins, William A. Seely, and William Stebbins. Additionally, Joseph Sampson, although not a director, was among the largest of the original shareholders of the later bank. During the 1820s, prospective bankers found that they were more likely to be able to successfully secure a state bank charter if the bank was part of a larger business. Accordingly, the founders used the manufacturing company (which produced chemicals such as blue vitriol, alum, nitric acid, camphor, and saltpeter, as well as medicines, paints, and dyes) as a means of securing a charter from the New York State legislature. In April 1824, the company amended its charter to allow Chemical to enter into banking, creating a separate division for the new activity. Melick was named the first president of the bank, which catered to merchants in New York City. Early investments by the bank were the Erie Canal and new roads.

In 1826, John Mason, one of the richest merchants in New York, became a shareholder of the bank. Mason succeeded Baltus Melick in 1831 as president. Mason was responsible for leading Chemical through the Panic of 1837. When a speculative bubble collapsed on May 10, 1837, banks suspended payment of gold and silver specie (coin). Although in the 1837 crisis Chemical followed others in suspending payments, Chemical was one of the earliest to resume payments in specie. Mason served as president until his death in 1839.

Isaac Jones, Mason's son in law, then took over. In 1844, when New York Chemical Manufacturing Company's original charter expired, the chemical company was liquidated and was reincorporated as a bank only, taking advantage of the Free Banking Act of 1838 and becoming the Chemical Bank of New York in 1844.

By 1851, the company sold all remaining inventories from the chemical division as well as the corresponding real-estate holdings.

During the Panic of 1857, while 18 New York banks closed in a single day, Chemical continued to make payments in specie. For a few days, it was the only bank to redeem notes in gold instead of in loan certificates; the bank got a nickname, "Old Bullion". The panic, which had hit banks and caused a number of failures, led banks across the country to suspend specie payments and turn to issuing paper promissory notes. Chemical's decision was highly unpopular among its fellow banks and led to the bank's temporary suspension from the New York Clearing House, of which Chemical was a charter member since 1853. Chemical developed a reputation for stability. This reputation proved extremely important in Chemical's growth during subsequent recessions during the 1860s.