Herbert Hayton Castens (23 November 1864 – 18 October 1929) was a South African rugby union footballer and cricketer.

In 1890-91 he also represented the Western Province cricket team at the fifth Champion Bat Tournament in Cape Town as an opening batsman and wicket-keeper.

Castens refereed the first tour match, which was a combined Cape Town rugby side against the British Isles.

[4] On 30 July, he captained South Africa in their first rugby international, against the British Isles team, which was played at the Crusader's Ground in Port Elizabeth.

He also refereed a number of other matches in the tour: Port Elizabeth Clubs, Cape Colony, and the third and final test at Newlands on September 5, and won four to nil by Britain.

[7] Castens later moved to Southern Rhodesia, where he worked as an advocate, and was later elected to the National Legislature, and served as secretary to the government for a number of years.