Samuel Richard Thayer (December 12, 1837 – January 7, 1909) was an American attorney and diplomat who served as United States Ambassador to the Netherlands.

[3] He graduated from Union College in Schenectady, New York, in 1860 and taught school for two years.

[4][5] A Republican, Thayer was interested in higher education and served as a member of the Minnesota State Normal School Board from 1873 to 1877.

[6] On March 19, 1889 President Benjamin Harrison appointed Thayer to succeed Robert Barnwell Roosevelt as Ambassador to the Netherlands.

[8] Besides maintaining a thriving law practice, Thayer was a successful businessman, including profitable investments in Minnesota real estate, and he made substantial donations to normal schools and colleges throughout the state.