阿西尔省（阿拉伯语：عسير‎）是沙特阿拉伯西南部的一个省，与也门接壤。由于位于高原地带（包括全国最高点，海拔3,207公尺的索达山），其气候与全国其他地区截然不同，比较凉爽潮湿。

'Asir or 'Aseer /ˈɑːsɪər/ (Arabic:عسير‎ ʿAsīr) is a region of Saudi Arabia located in the southwest of the country, named after the tribe of Asir which has the same name. It has an area of 81,000 km² and an estimated population of 2,190,000 It shares a short border with Yemen. Its capital is Abha. Other towns include Khamis Mushayt, Qal'at Bishah and Bareq. The regional governor is Faisal bin Khalid (appointed 16 May 2007), a son of King Khalid bin Abdulaziz. He replaced his cousin, Khalid Al Faisal in the post, who was made governor of Makkah Region on the same day.