Frederick Kingsbury Curtis I (February 3, 1863 – March 4, 1936) was a director of the Ann Arbor Railroad and was Secretary and Treasurer and a member of the Board of Directors of the United States & Porto Rico Navigation company from 1903 to 1906.
He was born on February 3, 1863 in New York City. He received his A.B. from Yale University in 1884, and became a member of the New York City Bar Association in 1886. On October 28, 1890 he married Marian Scott Hare, the daughter of Mr. & Mrs. J. Montgomery Hare. Their daughter Mary Emlen Curtis died in infancy. On June 14, 1905 he married Cornelia Day McLanahan (1873–1965) in Westminster, England. She was the daughter of George William McLanahan (1845–1908) and Helen Spencer Day (1848–1935). Their children were Helen Kingsbury Curtis, who married Herbert Pelham Curtis; and Cornelia McLanahan Curtis who married Laurence M. Lombard.
He died in Venice, Florida, on March 4, 1936. On March 9, 1936 he was buried at Woodlawn Cemetery.