Allen is a city in the province of Río Negro, Argentina. According to the 2001 census conducted by INDEC, it had 26,083 inhabitants.
The city is located on the left-hand, or northern, side of the Alto Valle of the Río Negro, near the valley's beginning at the confluence of the Neuquén and Limay rivers. It lies about 20 km (12 mi) west of General Roca and 35 km (22 mi) east of Neuquén.