Daniel Kan was a massive influence in homotopy theory, algebraic topology and category theory.
“…Kan had to serve in the army. But the army allowed him to do his service at the Weizmann Institute itself, and he could thus stay there for another two and a half years. His job offered him a lot of spare time, and he began to think about topology again. In the Spring of 1954, Samuel Eilenberg came from Columbia University on a visit to the Hebrew University in Jerusalem. (…) Kan knocked Eilenberg’s hotel room door, and explained his simplicial description of homotopy groups. Eilenberg asked him if he could prove the homotopy addition theorem, and Kan returned a week later with a proof. Eilenberg told Kan that he had a thesis there, engineered an ad hoc arrangement giving Kan the status of graduate student at the Hebrew University, and in the summer of 1954 Kan submitted his thesis. He formally received his PhD in 1955.”
Daniel M. Kan (1927–2013), Clark Barwick, Michael Hopkins, Haynes Miller, Ieke Moerdijk
Kan’s thesis seems to have been published across four short notes (I,II,III,IV) in the Proc. Nat. Acad. Sci., all up consisting of 13 pages. The thesis itself was (as far as I can tell from the Hebrew University’s library record) only 37 pages. More details expanding on part IV later appeared in the Annals of Mathematics (that was 32 pages long).
Perhaps not surprisingly, this pattern continued, with his student David Rector writing a PhD thesis at MIT in 1966, titled An unstable Adams spectral sequence, that is only nine pages long:
Rector’s thesis comprises a title page, an abstract page, a table of contents page, 7 pages of math, a bibliography page (8 refs.), and a biographical note page. The MIT library record’s “9 leaves” exclude the title/abstract/contents, which are not numbered. Except for some trivial changes in wording in the intro, the mathematical part is indeed identical to the 4-page Topology paper, vol. 5 (1966), 343-346. The thesis occupies more space since it’s manually typed; not including section titles, the 4 sections are respectively 18, 23, 42, and 36 typewritten lines
Comment at MathOverflow question “What is the shortest Ph.D. thesis?“, Timothy Chow
The “4-page Topology paper” has as one of its pages the references (and whitespace), and the first page is a summary of the result (restated later) and a little background material. So the real content of Rector’s PhD thesis is contained in two pages!
-set and that I called 
, got the nickname ‘Pete’. The terminal 
, got called “infinite Pete”. Some of these I don’t even know what they were in reaction to. But the skeleton one I know is because my frame rate was super super low before I got the OBS settings right, and the lag was … something else.
