Sometimes referred to as "the noted nerve specialist" or "the loony doctor", he is the most famous practitioner of psychiatry in Wodehouse's works, appearing in several Wooster-Jeeves stories and one Blandings story. Glossop represents one of the most fearsome authority-figures in the Wodehouse canon who is not an aunt. His character does not satirize any psychological fads in particular, but he manages to appear on the scene whenever one of Wodehouse's hapless heroes happens to be dressed or behaving in a way that might be construed to indicate insanity.
During the events of Uncle Fred in the Springtime, he is impersonated by Lord Ickenham, who borrows his identity to take lodgings in Blandings so as to resolve a series of complications. Sir Roderick, of course, suspects nothing.
Early in the series, Sir Roderick suspects Bertie of suffering from a mental disability, borne by the discovery of twenty-three cats in Bertie's bedroom as well as the remains of a cat-devoured salmon and his own top hat which had been snatched from him in the street. These items had been placed there by Bertie's cousins, Claude and Eustace Wooster after they had purloined them from their various owners in a bid to join a club. This notion was dispelled quite some time later, although not before complications ensued, by a complete explanation of the series of events.
Bertie's aunts frequently quote Sir Roderick when displeased with Bertie.
In Thank you, Jeeves, he and Bertie patch up their differences when both are seeking refuge after having been forced to black their faces with boot-polish for different reasons. He later becomes a friend of Bertie in the novel Jeeves in the Offing when he impersonates a butler named 'Swordfish' to hide his identity from Adela Cream as Bertie's Aunt Dahlia had brought him on to investigate the sanity of Mrs. Cream's son, Wilbur Cream. This spirit of brotherhood was brought on by shared experiences as they both had, while children, sneaking into their headmasters' studies and stealing biscuits (his being mixed while Bertie's were ginger-nuts). After he committed a gaffe by reacquiring a silver cow creamer that Tom Travers, Bertie's uncle had sold to Wilbur, he was forced to reveal his identity to the occupants of Brinkley Court and to place the blame, incorrectly, on Bertie Wooster.
- Scoring Off Jeeves (The Inimitable Jeeves)
- Sir Roderick Comes to Lunch (The Inimitable Jeeves)
- Rummy Affair Of Old Biffy (Carry On, Jeeves)
- Jeeves and the Impending Doom (Very Good, Jeeves)
- Jeeves and the Yule-tide Spirit (Very Good, Jeeves)
- Thank You, Jeeves
- Uncle Fred in the Springtime
- Jeeves in the Offing
- Jeeves and the Greasy Bird (Plum Pie)
- Usborne, Richard (2003). Plum Sauce: A P.G. Wodehouse Companion. New York: The Overlook Press. ISBN 1-58567-441-9.