Kálmán Szennai was born in 1973, in Budapest, where he studied piano and horn at the Béla Bartók High School of Music, and later, musicology and conducting at the Ferenc Liszt Academy of Music. He received his diploma in 1996, as a student of Ervin Lukács and Tamás Gál. After completing his studies, Géza Oberfrank hired him to work at the Hungarian State Opera, where he first served as a répétiteur, and later as a conductor. He has conducted at the Opera House regularly ever since. He has made guest appearances in Japan, Austria, Germany, and has been a recurring guest at the Budapest Operetta Theatre as well. He has conducted the Savaria Symphony Orchestra, the MAV Symphony Orchestra and the Budapest Festival Orchestra, and is a regular guest at the Jennersdorf and St. Margarethen opera festivals. He is a winner of the Komor, Juventus and Pless Awards. In 2018, he received the Hungarian Silver Cross of Merit, civil division. In 2023 he was awarded the Gusztáv Oláh Commemorative Plaque.