Clipper City is the name of a Baltimore, Maryland brewery. The brewery was established by Hugh Sisson in 1995, after previously operating Maryland's first brewpub, Sisson's. In 1998, Clipper City acquired the Oxford Brewing Company and began to produce organic recipes under that brand.

In 2010, Clipper City rebranded its expanding line of beers under the name Heavy Seas Beer and currently brews 24 beers under 3 different fleets (Clipper, Pyrate, and Mutiny Fleet). Loose Cannon Hop3 Ale, Heavy Seas Märzen, a repeat winner at the Great American Beer Festival (gold in 2007; silver in 2006), McHenry Lager, a bronze medal winner at the 2007 Great American Beer Festival, Small Craft Warning Uber Pils, a bronze medal winner at the 2004 Great American Beer Festival, and Heavy SeasGold Ale, a gold award winner at the 2010 World Beer Cup.