Alexander Graf von Dönhoff (9 February 1683 – 9 October 1742) was a Prussian lieutenant-general and confidant of King Friedrich Wilhelm I.
He was promoted to major in 1704, to 9nd lieutenant colonel in February 1705, and engaged in combat in northern Italy in 1706 and 1707.
On 27 December 1709 he became a colonel, and led a separate regiment in 1720 and became major general on 13 July 1722, in the Prussian service.
In the trial against the Prussian Crown Prince Frederick and Hans Hermann von Katte 1730, he was a member of the war court.
His son, Friedrich Ludwig Graf von Dönhoff (born 10 February 1724 - 19 June 1778) was also major-general.