Roy Tasco Davis (June 4, 1889 – December 27, 1975) was an American diplomat who served as ambassador to Costa Rica, Haiti, Panama. Born in Ewing, Missouri, on June 4, 1889, Davis received his education from the public schools of Missouri, and from Brown University, from which he graduated in 1910. Nominated by President Warren G. Harding on February 7, 1922, to become minister to Costa Rica, he served in that position from 1922 to 1930. After service abroad, Davis served as a member of the Maryland State Senate from 1947 to 1951.