The International Cosmic Ray Conference, or ICRC, is a physics conference organized biennially by the Commission C4 (Astroparticle Physics) of the International Union of Pure and Applied Physics (IUPAP) since 1947, where physicists from the whole world present the results of their research in Astroparticle Physics. The main topics of Astroparticle Physics are Cosmic Ray Physics, Gamma-Ray Astronomy, Neutrino Astronomy, Dark Matter Physics, Multi-Messenger Astrophysics, Solar and Heliospheric Physics, Astroparticle Physics Theory and Models, Experimental Methods, Techniques and Instrumentation and Outreach & Education in Astroparticle Physics. As part of the opening ceremonies, The O'Ceallaigh Medal is presented to a researcher who has made distinguished contributions to Cosmic Ray Physics. Also, the Yodh Prize and the Bhabha Medal and Prizes are awarded to senior members of the community. For young researchers, the Shakti Duggal Award and two IUPAP Young Scientist Awards are presented at each ICRCs. Proceedings are published for each conference. Some are, partially or in full, available online (see external links). The NASA's Astrophysics Data System (ADS) has started to gather these proceedings and publish them online on the ADS webserver. List of ICRCs 39th ICRC : 2025, Geneva, Switzerland 38th ICRC : 2023, Nagoya, Japan (webpage) 37th ICRC : July 12–23, 2021, Berlin, online conference, Germany (webpage) 36th ICRC : July 25 – August 1, 2019, Madison, Wisconsin, United States (webpage) 35th ICRC : July 12–20, 2017, Busan, South Korea (webpage) 34th ICRC : July 30 – August 6, 2015, The Hague, Netherlands (webpage) 33rd ICRC : July 2–9, 2013, Rio de Janeiro, Brazil (webpage) 32nd ICRC : August 11–18, 2011, Beijing, China (webpage) 31st ICRC : July 7–15, 2009, Łódź, Poland (webpage ) 30th ICRC : July 3–11, 2007, Merida, Yucatán, Mexico (webpage) 29th ICRC : August 3–10, 2005, Pune, India (webpage) 28th ICRC : July 31 – August 7, 2003 Tsukuba, Japan (webpage) 27th ICRC : August 8–15, 2001, Hamburg, Germany (webpage) 26th ICRC : 1999, Salt Lake City, United States 25th ICRC : 1997, Durban, South Africa 24th ICRC : 28 August – 8 September 1995, Rome, Italy (webpage) 23rd ICRC : 1993, Calgary, Canada 22nd ICRC : 1991, Dublin, Ireland 21st ICRC : 1990, Adelaide, Australia 20th ICRC : 1987, Moscow, USSR 19th ICRC : 1985, La Jolla, United States 18th ICRC : 1983, Bangalore, India 17th ICRC : 1981, Paris, France 16th ICRC : 1979, Kyoto, Japan 15th ICRC : 1977, Plovdiv, Bulgaria