Robert Christian Barthold Avé-Lallemant (25 July 1812 – 10 October 1884) was a German physician and explorer who was a native of Lübeck.

He earned his medical doctorate from the University of Kiel, and in 1836 relocated to Brazil, where he subsequently became director of a sanatorium for yellow fever patients in Rio de Janeiro.

In 1855 he returned to Germany, and enlisted as ship's doctor for the Austrian Novara expedition with a special recommendation from Alexander von Humboldt.

After the SMS Novara had crossed the Atlantic Ocean to South America in 1857, Avé-Lallemant disembarked in Rio de Janeiro, leaving the expedition.

In 1882 he published a book on the life of 17th century polymath Joachim Jungius, titled Das Leben des Dr. med.