Caryocolum cassella is a moth of the Gelechiidae family. It is found in the France, Germany, Austria, Switzerland, Denmark, Scandinavia, Poland, the Czech Republic, Slovakia, Romania, Estonia, Lithuania, Ukraine, Belarus and Russia. It is also found in North America]], where it has been recorded from Alberta, Saskatchewan, California and Nevada. A record from Hokkaido, Japan might also refer to this species. The larvae feed on Stellaria nemorum. They feed between spun shoots. Larvae can be found from May to June.