Founded in 1864, the bank was originally based in the Williamsburg neighborhood of Brooklyn, New York, and continues to operate with a strong market presence in this area.

Founded by William Grandy, Dime was established as a mutual savings bank serving the growing immigrant and low-income populations in the area.

Dime weathered a series of economic ups and downs as conditions in Williamsburg changed,[3] finally incorporating and becoming a publicly traded company on June 26, 1996.

At the same time, Dime acquired Conestoga Bancorp, Inc. and its wholly owned subsidiary, Pioneer Savings Bank,[4] making it the first simultaneous IPO/acquisition of its kind in the nation.

Having outgrown the First National Bank building, Dime moved its headquarters to a new development in the Williamsburg Bridge Plaza on the corner of Havemeyer and South 5th Street.