Theodore Frelinghuysen (1787–1862) was an American politician.
Theodore Frelinghuysen may also refer to:
Theodorus Jacobus Frelinghuysen (c. 1691–c. 1747), German-American Dutch-Reformed minister, theologian and the progenitor of the Frelinghuysen family in the USA Theodorus Jacobus Frelinghuysen II (1724–1759) or Theodorus Frelinghuysen, Jr., theologian in Albany, New York Theodore Frelinghuysen Seward (1835–1902) American musician and New Thought Christian writer in New York and New Jersey Theodore Frelinghuysen (New York socialite) (1860–1931), member of New York Society during the Gilded Age