- The Connolly Branch features Jacobean-style limestone architecture.
- The plaster moldings that decorate the ceilings are believed to have been inspired by the Rufford Abbey Library in England.
- Library services were first provided to Jamaica Plain’s Hyde Square in 1897 with the placement of a small book deposit in the rear of a neighborhood pharmacy at the corner of Lamartine and Paul Gore Streets.
- In 1905 the Boylston Station Reading Room opened, named for Boylston Railroad Station.
- The present branch location opened in 1932, designed by architects at Maginnis and Walsh.
- On December 12, 1940, the branch was renamed for Monsignor Arthur T. Connolly, a member of the Boston Public Library Board of Trustees and pastor of the neighboring Blessed Sacrament Church.