Ida Shepard Oldroyd (1856–1940) was an American conchologist and Curator of Geology at Stanford University for over 20 years, who curated what was for a time the second largest collection of mollusk shells in the world. Oldroyd and her husband, Tom Shaw Oldroyd, amassed one of the largest private shell collections in California. Ida was recognized as an active and early pioneer of conchology in the western United States. She was a charter member of the American Malacological Union, which she served as vice-president in 1934 and as honorary president from 1935 to 1940.