Bélik was born as Katalin Piláth in Piliscsaba, Pest, Hungary (then Austria-Hungary), on 17 September 1907 to an ethnically Slovak family. She married János Bélik and had three children.
Bélik worked in a cooperative and in forestry until her retirement aged 70. She was widowed at the age of 91, after a 67-year marriage. She could read without glasses until the age of 107.
Bélik died in the same town she was born on 4 November 2018 at the age of 111 years, 48 days. In addition to her three children, she was survived by seven grandchildren, 14 great-grandchildren, and five great-great-grandchildren.
Following the 13 May 2017 death of Dezsőné Kovács, Bélik became the oldest known living person in Hungary. After her own death, she was succeeded by Veronika Zsilinszki.
In October 2018, Bélik surpassed the age of Mária Höffner to become the known longevity recordholder of Hungary by residence. Her record was broken by Veronika Zsilinszki in March 2019.
Bélik’s age was validated by the European Supercentenarian Organisation on 26 February 2024.