Not to be confused with his grandfather Otto Wilhelm von Struve (1819-1905)

Otto Struve (August 12 1897 - April 6 1963) was a Russian-American astronomer. In Russian, his name is sometimes given as Otto Lyudvigovich Struve (Отто Людвигович Струве); however, he spent most of his life and his entire scientific career in the United States.

He was the grandson of Otto Wilhelm von Struve and great-grandson of Friedrich Georg Wilhelm von Struve, who were Russian astronomers of ethnic German origin. He was also the nephew of Hermann Struve.

He interrupted his studies to enlist for World War I, and then during the Russian Revolution he fought on the side of the White Russian forces and was wounded. When the White Russian forces were losing the civil war, he and his father Ludwig Struve were retreating with them into exile, but Ludwig Struve died in November 1920 in Sevastopol.

In a year and a half spent in exile in Gallipoli, Turkey and later Constantinople, he became an impoverished refugee and found work as a lumberjack. He learned that his brother Werner, also a White Russian officer, had died of tuberculosis and a younger sister had died of drowning. He wrote to his uncle Hermann Struve in Germany for assistance, but the latter had coincidentally also died a few months earlier. However, his widow asked her late husband's successor at the Berlin-Babelsberg Observatory to write to the director of Yerkes Observatory in Chicago, Edwin B. Frost, and a job offer soon resulted.

Otto Struve then moved to the United States and began a prominent career in astronomy. He did his Ph.D. dissertation in 1923 and his mother Elizaveta joined him that same year in the US. He became a citizen in 1927 and eventually succeeded Frost as director of Yerkes Observatory. Eventually, he served as director of four different observatories in all, in addition to serving as editor of the Astrophysical Journal and writing numerous books, in addition to his astronomical research.

He won the Gold Medal of the Royal Astronomical Society in 1944, the Bruce Medal in 1948, and the Henry Norris Russell Lectureship of the American Astronomical Society in 1957. He also served as president of the International Astronomical Union.

In 1925 he married the singer Mary Martha Lanning. They had no children, and thus the famous Struve astronomical dynasty came to an end.