Port Pirie is a small city on the east coast of the Spencer Gulf in South Australia, 223 km north of the state capital, Adelaide. Port Pirie is th…Port Pirie is a small city on the east coast of the Spencer Gulf in South Australia, 223 km north of the state capital, Adelaide. Port Pirie is the largest city and the main retail centre of the Mid North region of South Australia. The city has an expansive history which dates back to 1845. Port Pirie was the first proclaimed regional city in South Australia, and is currently the second most important and second busiest port in SA.