Colonel Arthur Hay, 9th Marquess of Tweeddale,, known before 1862 as Lord Arthur Hay and between 1862 and 1876 as Viscount Walden, was a Scottish soldier and ornithologist.
- Occupation
- ornithologist, scientific collector
- Citizenship
- United Kingdom of Great Britain and Ireland
- Born
- November 9, 1824
- Died
- December 29, 1878