Kata Pejnović was born in 1899 in the village of Smiljan near Gospić. She had actively participated in the party faction within societies Seljačko kolo (Peasants’ Wheel Dance) and Seljačka sloga (Peasant Unity). In 1936 she began to cooperate with and in 1938 became member of the Yugoslav Communist Party. After the establishment of the Independent State of Croatia, Ustashe killed her husband and her three sons. When armed resistance had started in Lika, Kata Pejnović worked on the establishment of the organization the Anti-fascist Women’s Front (AFŽ) in Lika. At the first session of the Antifascist Council for the National Liberation of Yugoslavia (AVNOJ) in Bihać in 1942, she was the only woman councillor at the AVNOJ. In the same year at the first AFŽ conference in Bosanski Petrovac, she was elected the president of the AFŽ of Yugoslavia. She was councillor at the First and Second Session of the State Anti-fascist Council for the National Liberation of Croatia (ZAVNOH), member of its presidency at the Third Session of the ZAVNOH in 1944 and member of the ZAVNOH presidency.
Kata Pejnović was the deputy speaker of the Sabor (Parliament) of the People’s Republic of Croatia. She was elected member of the Croatian Communist Party Central Committee, and was the deputy to Croatia’s and federal parliament. She was the Yugoslav People’s Army (JNA) reserve lieutenant-colonel and was one of the leading members of a number of social-political organizations. She died on 10 November 1966 in Zagreb. She was buried in the National Heroes’ Tomb at the Zagreb cemetery Mirogoj. Pejnović was declared war hero in 1968.