Carlotta Monterey (born Hazel Neilson Taasinge; December 28, 1888 – November 18, 1970) was an American stage and film actress. She was the third and final wife of playwright Eugene O'Neill.
She was born in San Francisco, California. Abandoned by her father, she was raised by an aunt from the age of four. After she won the title of "Miss California" in a beauty contest, she traveled to London to study acting with Sir Herbert Beerbohm Tree. She adopted the name Carlotta Monterey after her return to the United States at the start of World War I, and pursued a career in the theatre. She garnered disparaging reviews of her acting ability, but her beauty was much admired.
After divorcing her third husband, the illustrator Ralph Barton, in 1926, she became romantically involved with Eugene O'Neill. whom she had met in 1922 when she acted in a production of his play The Hairy Ape. They married in July 1929 in Paris. She remained with O'Neill for the rest of his life, and dedicated herself to maintaining his privacy. After his death in 1953, Carlotta expedited the publication of his autobiographical play Long Day's Journey Into Night, which O'Neill had instructed his publisher to withhold until 25 years after his death. The play was awarded the 1957 Pulitzer Prize for Drama, and is O'Neill's best known work.
A resident of the Valley Nursing Home in Westwood, New Jersey, Monterey died there on November 18, 1970.
- Soul-Fire (1925)