A series of 4‐ethynylcinnolines 3a–e was prepared by Sonogashira reaction of 4‐chlorocinnoline (1) with appropriate alkynes. Moreover, Suzuki coupling of 1 with boronic esters gave the corresponding 4‐arylcinnolines 5a–c. Detailed NMR spectroscopic data including unambiguous chemical shift assignments of all 1H, 13C, and 15N resonances of the obtained cinnoline derivatives are reported.