- Type: Clipper ship
- Hull: Composite
- Dimensions: 212 x 36 x 21 ft.
- Displacement: 991 tons
- Crew: 36
- Designer: Bernard Waymouth
- Built: Hall, Russell & Co., Aberdeen, Scotland, 1868
- Service: The largest of the tea clippers, she was built for George Thompson & Company of London. On her maiden voyage she sailed from London to Melbourne in 63 days, a record never beaten. (Her average over her first ten passages was just 69 days.) Continuing to Shanghai, she loaded tea and returned to Britain in only 91 days. Over eleven tea runs, she averaged 107 days back, and was the first of the returning tea clippers in 1873, 1874, and 1877.
Thermopylae had a famous rivalry with the clipper Cutty Sark, having the edge during their tea trading days. However, when steamers took over the tea route, they both moved into the wool trade with Australia via Cape Horn, and her best run of 76 days from Sydney was two days worse than the average 74 days of her rival.
In 1890 she was sold to a Canadian company and entered the rice trade between China and British Columbia. In 1896 she was sold to Portugal for use as a naval training ship and renamed Pedro Nunes, but she was in poor condition and ended up as a coal hulk on the Tagus. On 13 October 1907 she was towed to sea and torpedoed as a sort of naval funeral.