Portland Stone is limestone from the Jurassic period quarried on the Isle of Portland, Dorset. It is well known and has been extensively used thoughout the UK, notably in the rebuilding of London after the Great Fire. It has been and continues to be exported to many countries, and was used for the United Nations building in New York, for example.

Three main "Portland Beds" are quarried, producing a number of different stones. The Base and Whitbed beds are fine textured and contain few fossil remains, and so are popular for high quality work. The Roach bed is rougher with many fossils.

Also see

• List of stone
• Portland Admiralty Roach
• Portland Bowers Basebed
• Portland Bowers Lynham Whitbed
• Portland Bowers Saunders Whitbed
• Portland Grove Whitbed
• Portland Hard Blue
• Portland Independent Basebed
• Portland Independent Bottom Whitbed
• Portland Independent Top Whitbed
• Portland New Independent Whitbed