MB Financial Bank was a Chicago-based financial institution founded in 1911, originally known as Manufacturers Bank. It operated primarily in the Chicago metropolitan area, with 72 banking offices and one in Philadelphia. The bank provided a wide range of financial services, including consumer banking, corporate banking, private banking, investment banking, mortgage loans, wealth management, and credit cards.

MB Financial focused on building strong relationships with its customers, which included individuals, small- to medium-sized businesses, and corporate clients. The bank was publicly traded on Nasdaq under the ticker MBFI and had approximately $20 billion in assets before its acquisition by Fifth Third Bank in 2019. MB Financial was also known for its community involvement, sponsoring events like Bike the Drive in Chicago from 2010 to 2018.