Statue of Mehmet I in the city of Karaman
Mehmet I of Karaman (Turkish: Karamanoğlu Mehmet Bey), also known as Şemseddin Mehmet, was the second bey of Karaman Beylik, a Turkish principality in Anatolia in the 13th century. His father was Karaman Bey.
After the death of his father around 1261, Mehmet collaborated with the governor of Niğde to start a rebellion against the Mongols who were the suzerain of Seljuk lands. However after the governor of Niğde was killed by the Mongols, Mehmet lost his capital Ermenek. Nevertheless Mehmet continued fighting and in 1276 he defeated the combined forces of Mongols and Seljuks in a surprise attack in Göksu River valley.
Next year he allied himself with Baybars of Mamluks. In May he captured Konya the Seljuk capital. But instead of declaring himself as the sultan he supported Jimri, his puppet, as the sultan and in turn Jimri appointed him as the vizier of the Seljuks on 12 May 1277.  As a vizier Mehmet issued his famous firman which states that Turkish language replaced Persian language in government offices. But his service term in Konya was only about a month. Upon the news of approaching Mongol army, both Mehmet and Jimri fled from Konya. But Mongols chased him and during a clash in Mut Mehmet as well as his two sons were killed in August 1277. He was succeeded by his brother Güneri.
Mehmet is known as a devotee of the Turkish language. During his brief term as a vizier, he issued a firman dated 13 May 1277:
- Şimden girü hiç kimesne kapuda ve divanda ve mecalis ve seyranda Türki dilinden gayri dil söylemeye.
- From now on nobody in the palace, in the divan, council and on walks speak any language other than Turkish.
The university of Karaman city is named after him.(see Karamanoğlu Mehmetbey University)