Thomas (I) Szécsényi (Hungarian: Szécsényi (I.) Tamás; died 1354) was a Hungarian powerful baron and soldier, who rose to prominence during King Charles I's war against the oligarchs. He belonged to the so-called "new aristocracy", who supported the king's efforts to restore royal power in the first decades of the 14th century. He was the first member of the influential Szécsényi family.