PS Princess Elizabeth is a passenger-carrying paddle steamer which was built by Day, Summers and Company in 1927 for Southampton, Isle of Wight and South of England Royal Mail Steam Packet Company Limited, that is noted for being one of the Little Ships of Dunkirk, and is now a static floating restaurant in Dunkirk.

Day, Summers and Company was a British steam locomotive manufacturer and shipbuilder in the Southampton area. The company's history is complex and involves five men: William Alltoft Summers, John Thomas Groves, Charles Arthur Day, William Baldock and Nathaniel Ogle.