Sebastian Albert Freiherr von Sack (died 1828) was a German explorer and a chamberlain of Prussian nobility. In June 1821 he was honored with the title of "Graf (count)".
In 1805 he travelled to Surinam, where he made observations of the fauna, flora and local customs of the population. On his return journey back to Europe, he visited Washington DC, Philadelphia, New York City, Boston, et al. As a result of his travels he published Beschreibung einer Reise nach Surinam und des Aufenthaltes daselbst in den Jahren 1805, 1806, 1807 sowie von Rückkehr des Verfassers nach Europa über Nord-Amerika. In 1810 this treatise was translated into English as "A Narrative of a voyage to Surinam; of a residence there during 1805-1807; and of the authors return to Europe by the way of North America".
In 1817 Baron von Sack undertook a scientific mission to Egypt and the Middle East with poet Wilhelm Müller (1794–1827), and in 1820, on an expedition with Austrian consul Georg Christian Gropius (1781–1854), he procured the "Fragment from the tomb of Nikarete" in Athens. This antiquity is now housed at the Pergamon Museum in Berlin.
^Regarding personal names: Freiherr was a title, translated as Baron, not a first or middle name. Before 1919 preceding the first name, former titles are with people alive after 1919 dependent parts of the surname, thus preceding the main surname and not to be translated. The female forms are Freifrau and Freiin.