Oodla Wirra (formerly Penn) is a small town in the upper Mid North of South Australia. It is on the Barrier Highway approximately halfway from Adelaide to Broken Hill.
When the railway was built in 1880, a siding was provided, named Oodla Wirra. Soon after, a town was surveyed near the siding, but it was named Penn. This naming conflict continued until 1940, when the town was renamed Oodla Wirra, to match the railway station.