Kyriaki Papadopoulou (Greek: Κυριακή Παπαδοπούλου; born 19 May 1938), known by her stage name Marinella (Greek: Μαρινέλλα), is a Greek singer whose career has spanned several decades. She is well regarded due to her impressive vocal range. Since the beginning of her professional singing career in 1956, she has released 66 solo albums, and has also been featured on many albums by other musicians. She represented Greece in the Eurovision Song Contest 1974, becoming the first ever Greek entrant in the contest.

From 1956 to 2024, Marinella remained active for 68 years, performing in concerts and weekly shows at nightclubs. On September 25, 2024, at the age of 86, she suffered a severe hemorrhagic stroke while performing at the Odeon of Herodes Atticus in Athens, collapsing on stage. After four months of hospitalization, on January 21, 2025, she was discharged from the hospital and returned home.

Kyriaki Papadopoulou was born in the city of Thessaloniki in northern Greece. Her parents were Greek refugees from Constantinople. She is the fourth and last child of a large family, which despite its poverty, was rich in love and in artistic vein. The whole family gathered around the turntable and sang, while her father tried to teach children the steps of the waltz and the tango. From the age of four years singing on the radio broadcast in "Pediki Ora (Children's Hour)" and later did ads for shops such as "Melka" in Thessaloniki, earning her first pocket money. She participated in many performances of children's theatre.

At age 15, she gave up her budding career to finish school, but by seventeen, her passion for the theatre returned and she joined the artistic group of Mary Laurent, a "mpoulouki" (so called then the singer troupes that traveled Greece end-to-end for performances) and plays small roles. One day, the lead singer fell sick and sought Marinella as a replacement, who was willing to take the singer's place. Marinella then became the lead singer of the troupe. Additionally, she later joined the Military Theatre because the remuneration was better. At the same time she started her career as a singer at the "Panorama" centre of Thessaloniki, where Greek actor and singer Tolis Harmas coined the name "Marinella" for her, inspired by his song.

She released her first song in 1957, "Nitsa, Elenitsa (Little Helen)". Her early career was marked by her collaboration with singer Stelios Kazantzidis. Together they managed to become the greatest duet of Greece, unsurpassed even today. Starting at the night club "Luxembourg" in Thessaloniki where they enjoyed great success, they later moved to Athens, where they became widely known. They sang the songs of Mikis Theodorakis, Manos Hadjidakis, Vassilis Tsitsanis, Giorgos Mitsakis, Giorgos Zambetas, Apostolos Kaldaras, Theodoros Derveniotis, Stavros Xarchakos, Christos Leontis, whom are considered the best composers of the era.

Marinella married Stelios Kazantzidis on 7 May 1964 and they toured together in Germany and the United States. They divorced in September 1966. Marinella then began a solo career and eventually married singer Tolis Voskopoulos in 1974. This marriage also ended in divorce in 1981.

In October 1970, Marinella participated in the V Festival Internacional da Cançao Popular – Parte Internacion (FIC) in Rio de Janeiro, representing Greece with the song "Kyra Giorgena (Wife of George)", finishing 4th among 38 countries. On October 24, 1970, the Billboard wrote "Marinella from Greece, knows audiences in Athens clubs, carries enchantment in her songs and the warmth of the sun in her voice" (by Henry Johnston).

Marinella was the first Greek singer to participate in the International MIDEM Festival of 1973 in Cannes with three new songs composed by Stavros Xarchakos. She also participated in the Eurovision Song Contest in 1974, placing eleventh with the song "Krasi, thalassa kai t' agori mou" ("Wine, sea and my boyfriend"). Initially Greek rock band Nostradamos had won the first Eurovision participation contest run by the state broadcaster ERT to represent Greece at Eurovision. However the band was not allowed to compete at Eurovision due to a scandal, and Marinella was sent instead.