Naṣr al-Thamalī (Arabic: نصر الثملي) was an Abbasid military commander and governor (wali or amir) of Tarsus and the borderlands with the Byzantine Empire in Cilicia (al-thughur al-Shamiya).

As his nisba shows, he was a former ghulam of Thamal al-Dulafi, who was the governor of Tarsus and the borderlands with the Byzantine Empire in Cilicia in c. 923–932.^[1][2]

By 941, Nasr was himself governor of Tarsus. In winter of that year (December 941/January 942) he took advantage of a Byzantine expedition against Aleppo to raid Byzantine territory himself, returning with much plunder and prisoners, including senior Byzantine commanders.^[3] In October 946 he supervised the prisoner exchange with the Byzantines—headed by John the Mystikos and the magistros Kosmas — on the River Lamos on behalf of the Hamdanid emir Sayf al-Dawla, who had in the meantime become the new overlord of the Cilician marches. 2,482 Muslims were exchanged for an equal number of Byzantine captives; as the Byzantines held 230 prisoners more, they had to be ransomed with money.^[3][4]

• Lilie, Ralph-Johannes; Ludwig, Claudia; Pratsch, Thomas; Zielke, Beate (2013). Prosopographie der mittelbyzantinischen Zeit Online. Berlin-Brandenburgische Akademie der Wissenschaften. Nach Vorarbeiten F. Winkelmanns erstellt (in German). Berlin and Boston: De Gruyter.
• Stern, S. M. (1960). "The Coins of Thamal and of Other Governors of Tarsus". Journal of the American Oriental Society. 80 (3): 217–225. doi:10.2307/596170. JSTOR 596170.