Mont Agel, Mountain in the Alpes-Maritimes, France

Mont Agel is a mountain in the Maritime Alps on the French side of the border with Monaco, rising to 1,148 metres in the French sources and 1,151 metres in the French-language account. Its lower slopes carry dark green vegetation, while the upper part exposes pale grey and tan rock with sparse scrub. The ridge runs left to right with several rounded summits, the highest slightly left of centre, and descends to a lower shoulder on the right.

The mountain served as a military strongpoint during World War II, with fortifications built as part of the Alpine Line defense. These wartime structures remain visible on the slopes today.

The Monte Carlo Golf Club on the slopes celebrated its 100th anniversary in 2011 and formerly hosted the Monte Carlo Open. Its name comes from Monaco, though the course lies on the French side of Mont Agel. The surrounding slopes also hold Roc Agel, a summer residence bought by Prince Rainier III.

The summit is occupied by a military air base and cannot be reached on foot; the radar site remains active in automatic mode. The highest point of Monaco lies on the mountain's slopes on the Chemin des Révoires, reached via a staircase off rue Hector Otto and the Patio Palace lift, at about 161 metres. A strategic road from La Turbie to the summit was built in 1889–1890.

The summit holds Nice Air Base, built on the former Ouvrage Mont Agel of the Alpine Line; its radar watch continued automatically after the base closed in July 2012. On the slopes, Roc Agel was bought by Prince Rainier III as a summer family residence.