Boston Common is a beautifully maintained central public park in Boston, Massachusetts. It is sometimes erroneously referred to as "Boston Commons". Dating from 1634, it is the oldest city park in the United States. It is 50 acres (20 ha) of land. The Common is part of the Emerald Necklace of parks and parkways that extend from the Common south to Franklin Park in Roxbury. A visitors' center for all of Boston is on the Tremont Street side of the park.

The Common's purpose has changed over the years. Originally it was owned by William Blaxton (often given the modernized spelling "Blackstone") until it was bought from him by the city. During the 1630s, it was used as a cow pasture by many families living in Boston. However, this only lasted for a few years, as affluent families bought additional cows which led to overgrazing.

The Common was used as a camp by the British before the Revolutionary War, from which they left for the Battle of Lexington and Concord. It was used for public hangings up until 1817, most of which were from a large oak which was replaced with gallows in 1769.