Theodore de Lemos (1850, Holstein, German Confederation – 12 April 1909, New York City, New York, United States), son of Hermann and Maria Grothe De Lemos of Holstein, was an architect. He graduated with honors from the Berlin Royal Academy of Buildings, and was famous for his designs in three countries, Germany, Mexico, and the United States. In 1981, de Lemos left Germany and settled in New York, where he married Margaretta Becker and had a daughter, Marie Katherine.