Moses Székely (Hungarian: Székely Mózes; c. 1553 – 17 July 1603) was Prince of Transylvania in 1603.
He was a military leader under Prince Sigismund Báthory. After the latter's third and final abdication in 1601, Transylvania was controlled by the mercenaries of Habsburg general Giorgio Basta. In April 1603, Székely instigated the native Transylvanian forces to rebel and, with the support of Turkish-Tartarian auxiliary forces, routed Basta's troops. On 8 May 1603, Székely claimed the title of a Prince of Transylvania, but his rule proved unstable, as his Tartarian mercenaries outdid Basta's troops in cruelty and Radu Șerban, the new Voivode of Wallachia attacked as an ally of the Habsburgs.