Alamnagar Union () is a union of Gopalpur Upazila, Tangail District, Bangladesh. It is situated at 42 km north of Tangail.
According to Population Census 2011 performed by Bangladesh Bureau of Statistics, The total population of Alamnagar union is 19752. There are households 5281 in total.
The literacy rate of Alamnagar Union is 41.2% (Male-43.4%, Female-39.1%).