Northern Trust Corporation is a financial services company headquartered in Chicago, Illinois. It provides investment management, asset and fund administration, and fiduciary and banking services through a network of 85 offices in 18 US states and 20 international offices in North America, Europe, and the Asia-Pacific. As of March 31, 2017, the company had $121 billion in banking assets, $7.1 trillion in assets under custody and $1.0 trillion in assets under management.

Northern Trust is ranked #501 on the Fortune 1000 and is on the list of largest banks in the United States.

Other than M&T Bank, Northern Trust was the only bank in the S&P 500 Index not to lower its dividend during the financial crisis of 2007–2008.

The company strives to give approximately 1.5% of its pre-tax profits to charities every year. In the 10 years preceding 2014, the company gave over $120 million in support of non-profit organizations.

Northern Trust was founded in 1889 by Byron Laflin Smith in a one-room office in the Rookery Building in The Loop, Chicago, with a focus on providing trust and banking services for the city's prosperous citizens. Smith provided 40% of the bank's original capitalization of $1 million, and the original 27 shareholders included such businessmen and civic leaders as Marshall Field, Martin A. Ryerson, and Philip D. Armour. Intimately acquainted with the operations of the bank, these men would personally examine Northern's assets and records at each year's end.

The flamboyant decade of the 1920s came to a sudden halt with the Wall Street Crash of 1929. As economic troubles swept across the country, one bank after another closed. Two days after the inauguration of Franklin D. Roosevelt, on March 6, 1933, the Emergency Banking Act closed all banks in the United States. When they reopened a short time later, there was a great deal of uncertainty as to what might occur. Fortunately, the people in line outside the Northern bank offices were there to deposit instead of withdraw money. Northern's conservative policies had served it well during the 1920s.

By 1941, nearly half of all the bank's commercial accounts were drawn from outside the Chicago metropolitan area. During World War II, Northern once again took part in the government's war bond drives, and also provided loans for manufacturing war materials under special government programs. The war created more opportunities for the bank; all sectors of its business expanded, and by 1945 the Northern Trust had doubled in size.

The years after World War II brought even greater prosperity to the bank as it continued to expand its services. Still under the direction of Solomon Smith, management at the bank became more aware of electronic data processing and how this new technology could revolutionize the banking industry. During the 1950s, Northern was at the forefront of developing numerous automated banking services, including the first fully automated financial statements for trust clients.

When Solomon Smith died in 1963 and his son, Edward Byron Smith, assumed leadership of the bank, assets totaled more than $1 billion.

Throughout the 1970s and 1980s, Northern Trust acquired companies and expanded into Florida, Arizona, California and Texas.

Edward Byron Smith retired as chief executive officer in 1979. He was succeeded by E. Norman "Bud" Staub. A few years later, Philip W. K. Sweet took over but he resigned in 1984.

In 1984, Weston Christopherson, former CEO of Jewel took the helm. He is credited with guiding the bank through a difficult period when sour loans to Latin American countries were hurting profits. When oil prices dropped suddenly in the early 1980s, many South American nations realized they could not pay off their enormous bank loans. Northern suffered uncharacteristically high losses. Aggressive management, loan reserves, and write-offs enabled the bank to restore its asset quality. During Christopherson's six years at Northern Trust, profits rose from $34 million to $113 million. At the time of his retirement in 1990, the company was the 11th most profitable of the 100 largest banks in the United States.

When company veteran David W. Fox took over as CEO in 1990, he was only the 7th chief executive in the bank's 100-year existence. William A. Osborn was named president and chief operating officer in 1993 and became chairman and chief executive officer, in addition to president, in 1995.

Osbourne stepped down as president in 2006 and as CEO on January 1, 2008. Frederick H. "Rick" Waddell then became president and CEO.

Effective January 1, 2018, Michael O'Grady will be the chief executive officer of the company.

Over 20% of the wealthiest families in the United States are clients of Northern Trust. It is also one of the largest global custodians in the world, serving the asset servicing needs of corporate and public retirement, foundations, endowment, fund managers, insurance companies and government funds.

Locations include: Abu Dhabi, Amsterdam, Bangalore, Beijing, Dublin, Frankfurt, Guernsey, Hong Kong, Kuala Lumpur, Limerick, London, Luxembourg, Manila, Melbourne, Pune, Riyadh, Seoul, Singapore, Stockholm, Sydney, Tokyo and Toronto. Within the United States, locations include Illinois, Arizona, California, Colorado, Connecticut, Delaware, Florida, Georgia, Massachusetts, Michigan, Minnesota, Missouri, Nevada, New York, Ohio, Texas, Washington and Wisconsin.

The company sponsors The Northern Trust, a PGA Tour event that is the first event in the FedEx Cup playoffs. For 9 years, until 2017, it was the sponsor of the Los Angeles Open PGA Tour event.

C&IS is a global provider of asset servicing, asset management, and related services to corporate and public retirement funds, foundations, financial endowments, fund managers, insurance companies, and government funds. C&IS also offers a commercial banking services, with emphasis on developing and supporting institutional relationships in large and mid-sized corporations, and financial institutions. Client relationships are managed principally through the Chicago, London, Singapore, and Toronto branch locations, with other operations or representative offices in New Jersey, Republic of Ireland, the Channel Islands, the Netherlands, China, and Australia. Asset servicing relationships managed by C&IS often include investment management, securities lending, transition management, and commission recapture services provided through Northern Trust Asset Management. C&IS also provides related foreign exchange services in the U.S., U.K., Guernsey, and Singapore.

Wealth Management provides personal trust, investment management, custody, and philanthropic services; financial consulting; guardianship and estate administration; qualified retirement plans; and private and business banking. Wealth Management focuses on high-net-worth individuals and families, business owners, executives, professionals, retirees, and established privately held businesses in its target markets with assets typically exceeding $75 million.

Wealth Management services are delivered through a network of 85 offices in 18 U.S. states as well as offices in London and Guernsey.

Northern Trust Asset Management provides investment management services. Clients include institutional and individual separately managed accounts, bank common and collective funds, registered investment companies, non-U.S. collective investment funds and unregistered private investment funds. It offers both active and passive equity and fixed income portfolio management, as well as alternative asset classes (such as private equity and hedge funds of funds) and multi-manager products and services.