Harriet Sylvia Ann Howland Robinson Green Wilks (January 7, 1871 – February 5, 1951) was one of the wealthiest women in the United States.

[1] Harriet Sylvia Ann Howland Robinson Green was born in London, England on January 7, 1871.

On February 23, 1909, Sylvia, then 38 years old, was married to 63-year-old Matthew Astor Wilks (1844–1926) in Morristown, New Jersey.

[2] Although Wilks was worth approximately $2,000,000 in his own right, her mother insisted that they have a prenuptial agreement waiving his right to inherit Sylvia's fortune.

[5] Sylvia, who was then living at 998 Fifth Avenue,[6] died at New York Hospital on February 5, 1951,[7] and was buried alongside her husband at Immanuel Cemetery in Vermont.