Kelishahar Union () is a union, the smallest administrative body of Bangladesh, located in Patiya Upazila, Chittagong District, Bangladesh. The total population is 16,095.
The area of Kelishahar Union is 10,803 acres (43.72 square kilometres).
According to the 2011 Bangladeshi census, Kelishahar Union had a population of 16,095, of which 7,654 were males and 8,441 were females. The total number of households was 3,598.
Kelishahar Union is located in the northern part of Patiya Upazila, approximately 6 kilometres from the upazila headquarters. It is bounded to the west by Dhalghat Union and Dakhin Bhushi Union, to the south by Patiya Municipality and Haidgaon Union, to the east by Haidgaon Union and Ahla Karaldanga Union of Boalkhali Upazila, and to the north by Ahla Karaldanga Union of Boalkhali Upazila.
Kelishahar Union is the 11th Union Parishad under Patiya Upazila. The administrative activities of the union fall under the jurisdiction of Patiya Thana. It is part of Chittagong-12 (Constituency 289) of the National Parliament of Bangladesh. The villages in the union are as follows:
According to the 2011 Bangladeshi census, Kelishahar Union had a literacy rate of 51.7%.