Ajgana Union () is a union of Mirzapur Upazila, Tangail District, Bangladesh. It is situated southeast of Mirzapur and southeast of Tangail, the district headquarters.
According to the 2011 Bangladesh census, Ajgana Union had 7,463 households and a population of 32,949. The literacy rate (age 7 and over) was 51.2% (male: 54.5%, female: 48%).