Nagda Simla Union () is a union of Gopalpur Upazila, Tangail District, Bangladesh. It is situated 8 km southeast of Gopalpur and 55 km north of Tangail, the District headquarters.
According to Population Census 2011 performed by Bangladesh Bureau of Statistics, the total population of Nagda Simla union is 31436. There are 7624 households in total.
The literacy rate of Nagda Simla Union is 47.5% (Male-50.3%, Female-44.7%).