Collection of material relating to the theatre, with specific reference to Scotland, 1757-1981. Includes:
- Programmes 1881-1952, including: Royalty Theatre 1881, Royal Lyceum, Edinburgh 1884-1891, Citizens' Theatre, Glasgow University Dramatic Clubs and Groups, 1943-1952
- Playbills 1817-1866
- Various artwork including: album of cartoons and drawings 1881-1882
- Papers relating to Henry Siddons, including an obituary 1815
- Various albums and scrapbooks containing images of Victorian and Edwardian personalities, undated
- Theatre memorabilia, undated
- Newsletters of Citizens' Theatre, 1946-1957, Scottish Society of Playwrights, 1979-1981, Glasgow Theatre Club, 1979
- Magazines including: Scottish Theatre News, 1981, Scottish Theatre, 1969-1973, International Theatre Information, 1977-1980
- Papers relating to the publication and research for English Theatrical Literature c. 1949-1969
- Correspondence and other papers relating to organisations in which Arnott had connections c. 1960-1983, including: the International Theatre Institute, International Federation for Theatre Research, Socit Internationale des Bibliothques et des Muses des Arts du Spectacle, The Theatres Trust, United Nations Educational Scientific and Cultural Organisation, the Royal Scottish Academy of Music and Drama, Arts Council, Scottish Ballet, Society for Theatre Research, Tron Theatre Club, British Theatre Institute, Third Eye Centre, Glasgow, and the Citizens' Theatre
- Papers of the Eden Court Theatre, Inverness, undated
- Financial papers and minutes of the Citizens' Theatre, undated
- Miscellaneous correspondence, 1940-1981.