G. H. HARDY, M.A., F.R.S.
FELLOW OF NEW COLLEGE
SAVILIAN PROFESSOR OF GEOMETRY IN THE UNIVERSITY OF OXFORD
LATE FELLOW OF TRINITY COLLEGE, CAMBRIDGE G. H. HARDY, M.A., F.R.S.
FELLOW OF NEW COLLEGE
SAVILIAN PROFESSOR OF GEOMETRY IN THE UNIVERSITY OF OXFORD
LATE FELLOW OF TRINITY COLLEGE, CAMBRIDGE[1] https://www.economics.soton.ac.uk/staff/aldrich/Doc1.htm
[2] https://royalsocietypublishing.org/doi/10.1098/rsbm.1949.000...
https://en.wikipedia.org/wiki/John_Edensor_Littlewood
Edit: The Mathematics Genealogy Project lists Littlewood as an M.A. as well.
One of my Cambridge professors was Mr. Phil Woodland, an international authority on automatic speech recognition. When I asked him why he had no Ph.D., he shrugged and said he was too busy with his research work, so he "never found the time". Meanwhile, he got promoted to Professor [1].
Another noteworthy fact about Oxford and Cambridge that people from elsewhere may not realize is that they award an M.A. "for free" to Bachelor students after 5 years have passed, so you effectively get two degrees for the price of one.
There are a small number of people in academia that are so good that they are effectively exempted from the requirement for traditional credentials- because everyone in the field knows who they are and will make a custom position for them anywhere that bypasses traditional requirements and recruitment.
Source: Why I don't like the PhD system (95/157)