It is managed by the non-profit Lenox Library Association, founded in 1856, and is located at 18 Main Street, in the former Berkshire County Courthouse that is listed on the National Register of Historic Places.

In the early 20th century, novelist Edith Wharton worked in the library and befriended Kate Spencer, who served as partial inspiration for her 1911 novel Ethan Frome.

A substantially larger addition, made in 1889, extends to the rear of the building; it is also topped by a hip roof with cupola.

[5] The main block was built in 1815–16 to a design by Isaac Damon of Northampton, and served as the Berkshire County Courthouse until 1869, when that function was moved to Pittsfield.

Additional tenants during the late 19th century included the offices of lawyers and politicians, and the town's first telephone exchange.

[6] The Keator Vault contains local historic items, unique photographs, and functions as temperature controlled preservation archive for rare materials.

[6] The biggest users of the music collection at the Lenox Library are the Boston University Tanglewood Institute students.

This collection, housed in the Keator Vault, "consists of 745 original glass plate and film negatives of the Berkshire estates, as well as a complete set of study prints.

[7] In the summer the Lenox Farmers Market takes place near the park typically between the end of May through September.