In the early 1700s, Anthony Palmer, an English businessman working in Barbados, purchased a large tract of land that he called Kensington after a suburb of London. Early residents were shipbuilders and fishermen, but by the 1830s Kensington had become the textile center of Philadelphia. In 1922, the Frankford elevated line began operation, passing through Kensington Avenue. The textile mills moved south by the end of the 1930s.

Kensington Branch was originally known as Frankford Avenue Branch, Branch Number 3 of the Free Library system. It opened on May 21, 1894 at 1856 Frankford Avenue. The name was changed to the Kensington Branch in 1900. In August 1902 it moved to an empty church building at 2055 East Dauphin Street where it remained for 51 years. In 1953, pending completion of plans for a new location, the agency moved to a small rented shop at 2508 North Front Street.

The current Kensington Branch opened on July 20, 1956. It was renovated in 1997 as part of the "Changing Lives" campaign, which refurbished branches and brought Internet service to every library. When you visit, take a look at the mosaic in the meeting room. It was designed by Network Arts and created with the help of neighborhood children.