Katerina Helmi (Greek: Κατερίνα Χέλμη, Athens, 12 August 1939 - Kifissia, 15 April 2023) was a Greek actress. She became widely known to the Greek audience through roles in some of the most beloved films of Greek cinema. Her first appearance in cinema was in 1957 in the film Barbagiannis the Pitcher, but her greatest success is The Red Lights. She was also the rival of Aliki Vougiouklaki in the film Our Love. During her career, she has participated in more than 25 films and 4 television series. She has also written several books. Her husband was the professor and academic Konstantinos Svolopoulos. Unlike her husband Konstantinos Svolopoulos, who was a close friend of Konstantinos Karamanlis and director of the Karamanlis Foundation, Katerina Helmi was politically active in PASOK, as a member of the Trade Union Committee of Scientists-Artists. In the 1994 municipal elections, she was elected as a municipal councilor of the Municipality of Athens with the faction of Theodoros Pangalos. She died on 15 April 2023.