Jonas Coldewy Ahlgren was a Swedish military (lieutenant) and lithographer.

Ahlgren was one of the first to use the lithographic technique in Skåne and was active as an illustrator for various grove prints. He illustrated Anders Gustaf Dahlbom's entomological treatises and he lithographed Kilian Zoll's portrait of Dr. A. P. Gullander in 1848. He was hired by Carl Georg Brunius as a draughtsman for the renovation of Lund Cathedral in the 1830s. Ahlgren lived most of his life in Copenhagen and probably died there. Ahlgren is represented at the National Museum in Stockholm. He is buried in the Old Cemetery in Malmö.