János Kéry was born in 1974 into a family of musicians. He started his piano and composition studies in Debrecen (Hungary). He continued in the USA at Boise State University with Madeleine Forte, Jim Cook, and Alexander Peskanov, and later in the Piano Department of the Liszt Academy in Budapest with István Lantos, András Kemenes, and Márta Gulyás, where he graduated with honours. In 2000, he was awarded the Artisjus Prize and became a member of the Hungarian Society for Music. He won Eötvös and DAAD scholarships for his postgraduate studies at the University of Music in Saarbrucken, Germany, with Thomas Duis, where he gained two further Masters degrees in 2001 (Konzertreife) and 2015 (Solistenprüfung). He was awarded the degree of DLA (Doctor of Liberal Arts) in May 2015 by the Liszt Academy in Budapest with the guidance of Péter Nagy and Ilona Prunyi, where he received his Habilitation in 2024 as well. 

From 2004 to the present, he has been teaching piano at the Liszt Academy in Budapest. He has given master classes in Quindao (China), Sankt Wendel (Germany), Granada (Spain), the University of Silesia (Poland), and at the State Music Academy of Mexico. He has been a juror at the Ignác Semmelweis Music Competition and the Zoltán Kodály Piano Competition in Budapest and the Angelica Morales National Piano Competition in Mexico City.

He has given concerts with Boise State University Symphony, the BM Duna Symphony Orchestra, the Debrecen and the Szombathely Symphony Orchestras, and the Sándor Frigyes and the Savaria Chamber Orchestra. He is a frequent performer in the contemporary music Mini-Festival in Budapest. He has performed in the concert halls of the Liszt Academy, the Vigadó, the Palace of Arts in Budapest, in Yale University in the USA, the Bellas Artes concert center in Mexico City among others as well as in many different countries: Hungary, Slovakia, Poland, Romania, Austria, Germany, France, Netherlands, UK, Spain, Finland, Italy, USA, Canada, and Mexico.

He has made recordings for radio and given live broadcasts on BSU Radio (USA), Bartók Radio (Budapest), and Saarbrücken Klassik Radio (SR2).