Jia, Xingde
- Texas State University - San Marcos. Combinatorial number theory: the problem of thin bases for finite groups, Sidon sequences. Publications, teaching information.
- http://erdos.math.txstate.edu/

Járási István
- University of Debrecen, Department of Algebra and Number Theory. Publications, thesis.
- http://www.math.klte.hu/~ijarasi/

James, Kevin
- Clemson University. Fourier coefficients of modular forms and arithmetic applications. Publications, resources.
- http://www.math.clemson.edu/~kevja/

Jacobson, Eliot
- Unicersity of California, Santa Barbara. Algebraic, Elementary and Computational Number Theory. Teaching information, resources.
- http://www.cs.ucsb.edu/~teliot/

Jarvis, Frazer
- University of Sheffield. Algebraic number theory and algebraic geometry; in particular, the theory of modular forms and Galois representations. Publications, teaching materials.
- http://www.sheffield.ac.uk/~pm1afj/

Janusz, Gerald J.
- University of Illinois at Urbana-Champaign. epresentation theory of finite groups, algebraic number theory, Brauer groups, ring theory, algebraic coding theory. Selected publications, teaching material.
- http://www.math.uiuc.edu/~janusz/

Jackson, Terence
- University of York. Geometry of numbers, distribution of values of forms.
- http://www-users.york.ac.uk/~thj1/

Jarden, Moshe
- University of Tel Aviv, Israel. Field arithmetic. Contains articles, notes, and course information in postscript format.
- http://www.math.tau.ac.il/~jarden/

Jones, John
- Arizona State University. Algebraic number theory: Iwasawa theory, the arithmetic of elliptic curves, Galois theory; questions in computational number theory. Tables of number fields of small degree. "Discovering number theory" course materia
- http://math.la.asu.edu/~jj/

Juricevic, Robert
- University of Waterloo. Analytic number theory. Publications.
- http://www3.sympatico.ca/robert.juricevic/

Jiang, Dihua
- University of Minnesota. Automorphic Forms, Representation Theory, Number Theory.
- http://www.math.umn.edu/~dhjiang/

Jochnowitz, Naomi
- University of Rochester. Algebraic number theory, modular forms, p-adic modular forms.
- http://www.math.rochester.edu/people/faculty/what/