Yoko Caroline is a former Japanese child actor and voice actor known for her work in the 1970s. She was born on August 10, 1962, in Tokyo, to an American father employed by a shipping company and a Japanese mother. She began her career in entertainment at the age of three, joining the theater company Gekidan Wakakusa with her older brother. As a child, she appeared in various television dramas, including the Yomiuri TV program Papa no Okurimono, and worked as a child model for print advertisements and commercials, such as for the dog food brand Vita-One. She also appeared on an NHK educational English program and was a regular panelist on a mystery quiz show sponsored by Sekisui House in the early 1970s.

Her most recognized voice role from this period is Cosette in the 1979 anime television special Jean Valjean Monogatari, an adaptation of Victor Hugo's Les Misérables. In this production, she is credited as Caroline Yoko.

Yoko Caroline attended the American School in Japan in Chofu, Tokyo, from kindergarten through high school, graduating in 1980. She then enrolled at Sophia University in Tokyo to study psychology but left after one year. At the age of 19, she moved to the United States to continue her education, effectively putting her entertainment career on hold. She graduated from Oregon State University with a degree in mathematical sciences and mathematics. In 1986, she entered the graduate school in the Department of Computer Science at Oregon State University to research artificial intelligence, eventually earning a master's degree. After completing her graduate studies, she joined the Hewlett-Packard Company as a researcher in artificial intelligence and was residing in Colorado.