| Number Theory Centres: Listed in the Number Theory Web. |
| (Austria) Technical University of Graz: Algorithmic and Probabilistic Number Theory Research Group. Members, research interests. |
| (Austria) University of Natural Resources, Vienna: Number theory group led by Werner Georg Nowak. Members, research interests, publications, links. |
| (Austria) University of Vienna: Johannes Schoißengeier's number theory research group. Members, research interests, links to other Austrian number theorists. |
| (Canada) CICMA, Concordia University, Montreal: Number Theory Page. Members, seminars, preprints. |
| (Canada) McMaster University: Algebra/Number Theory Seminar. Meetings, abstracts. |
| (Canada) Queen's University, Kingston: Algebra and Number Theory Group. Members, research interests. |
| (Canada) University of British Columbia: Number Theory group. Members, research areas and meetings. |
| (Canada) University of Toronto: Number Theory/Representation Theory Seminar. Schedule of meetings. |
| (China) Shandong University: Number theory research group. Members, research interests, courses, events. |
| (Croatia) University of Zagreb: Seminar on Number Theory and Algebra. Members, seminars, links. |
| (Europe) Arithmetic Algebraic Geometry: A European network of 12 working groups from 6 countries. |
| (Europe) GTEM: Galois Theory and Explicit Methods in Arithmetic: Research training network coordinated in Paris, uniting twelve teams from July 2000 until June 2004. |
| (Finland) University of Turku: Number Theory Group. Members, research interests. |
| (Germany) Clausthal University of Technology: Institut für Mathematik - Number Theory Research Group. People, research topics. |
| (Germany) Technische Universität, Berlin: Algebra and Number Theory: the KANT group. Members, software (KANT/KASH), publications. |
| (Germany) University of Heidelberg: Algorithmic Algebra and Number Theory. Members, research, activities, software, links. |
| (Germany) University of Regensburg/Leipzig: Algebraic Cycles and L-Functions research group. People, preprints, seminars, workshops, positions, news. |
| (Germany) University of Siegen: Algebra and Number Theory group. Members, research interests. |
| (Hungary) Alfréd Rényi Institute of Mathematics, Hungarian Academy of Sciences: Number Theory research group staff. |
| (Hungary) Eötvös University, Budapest: Department of Algebra and Number Theory. Members pages. |
| (Hungary) Lajos Kossuth University, Debrecen: Department of Algebra and Number Theory. Staff list. |
| (Israel) Ben Gurion University of the Negev: Number Theory and Algebraic Geometry Research Group. Members, research interest, seminars. |
| (Italy) University of Pisa: Number Theory Group. Research interests and members. |
| (Japan) Okayama University: Number Theory Group. Members. |
| (Lithuania) Vilnius University: Department of Probability Theory and Number Theory. |
| (Netherlands) CWI, Amsterdam: Computational number theory group. Members, research interests, publications. |
| (Netherlands) University of Leiden: Number theory research group. Staff, events, links. |
| (Poland) Polish Academy of Sciences: Department of Number Theory. Members, research interests, publications. |
| (Russia) Steklov Institute, Moscow: Department of Number Theory. History, research projects, profiles. |
| (Russia) Steklov Institute, St. Petersburg: Laboratory of Number Theory. Research interests. |
| (Singapore) National University: Algebra and Number Theory Seminar. Schedule of meetings. |
| (Slovakia) Comenius University, Bratislava: Department of Algebra and Number Theory. Research topics, contact information. |
| (South Africa) The John Knopfmacher Centre for Applicable Analysis and Number Theory, University of the Witwatersrand: Members, research interests, preprints, meetings. |
| (Spain) Seminari de Teoria de Nombres de Barcelona (UPC): Members, research topics, publications, schedules. |
| (Sweden) Uppsala University: Mathematics III research group: quantum chaos and number theory. |
| (UK) Cardiff University: Number Theory Group. Members, research interests, advice to research students. |
| (UK) King's College, University of London: Number Theory Group. Staff, meetings, preprints. |
| (UK) Nottingham University: Number Theory and Arithmetic Geometry research group. Research interests, members, visitors, meetings. |
| (UK) Royal Holloway, University of London: Research areas (mainly analytic/combinatorial), members. |
| (UK) University of Bristol: Number Theory group. Staff, students, events, links. |
| (UK) University of Cambridge: Number Theory Seminar. Meetings. |
| (UK) University of Durham: Geometry and Arithmetic Group. Members, meetings, preprints. |
| (UK) University of East Anglia: Number Theory research. |
| (UK) University of Glasgow: Number Theory and Combinatorics. Staff, research interests. |
| (UK) University of Oxford: Number Theory Group. Members, publications, meetings. |
| (UK) University of York: Number Theory Research Group. |
| (Ukraine) Tavrical National University: Department of Algebra and Number Theory. Members, research interests, publications. |
| (USA) Boston University: Algebra and Number Theory Research Group. Members, research interests, seminars, courses. |
| (USA) Brown University: Number Theory/Arithmetic Geometry Seminar. Members, meetings. |
| (USA) Caltech: Underground Number Theory Seminar. Schedule of meetings. |
| (USA) New York Joint Number Theory Seminar: Rotates between Columbia University, CUNY Graduate Center and NYU. |
| (USA) Penn State: Algebra and number theory group. Members, seminars, preprints, links. |
| (USA) Southwestern Center for Arithmetical Algebraic Geometry: Based at the University of Arizona, in collaboration with the Universities of New Mexico, Southern California, and Texas. Annual conference. |
| (USA) Texas A and M University: Combinatorics/Number Theory Directory. |
| (USA) University of California Irvine: Number theory seminar. Meetings, study groups, links. |
| (USA) University of California, Los Angeles: Number Theory Group. Members, events, resources. |
| (USA) University of California, Santa Barbara: Arithmetic and Geometry Seminar. Meetings. |
| (USA) University of California, Santa Cruz: Number Theory Seminar meetings. |
| (USA) University of Georgia: Number Theory and Arithmetic Geometry Group. Members, seminars. |
| (USA) University of Illinois at Urbana-Champaign: Number Theory faculty, visitors, meetings, courses, events. |
| (USA) University of Rochester: Algebra and Number Theory Group. Members, research interests, seminar schedule. |
| (USA) University of South Carolina: Number Theory Group. Members, research interests, courses, links. |
| (USA) University of Texas: Number Theory Group. Members, meetings, software. |
| (USA) University of Wisconsin, Madison: Algebra, Combinatorics and Number Theory Group. Members, seminars. |
| (USA)University of Michigan: Graduate Program in Number Theory. Staff, research interests, courses, seminars. |
Classical
