Back Bay is an officially recognized neighborhood of Boston, Massachusetts. It is an upscale residential, retail, and commercial office district.

Back Bay and neighboring Beacon Hill are considered Boston's most expensive neighborhoods, with townhouses regularly selling for millions of dollars . Popular upmarket shopping destinations include Newbury and Boylston Streets as well as the Prudential Center and Copley Place malls.

Architecturally the neighborhood is dominated by Victorian brownstone buildings in its northern, more residential portion; the southern part of the neighborhood is far more commercial and is home to some of Boston's tallest skyscrapers.