The Agassizhorn is a mountain of the Bernese Alps in Switzerland.

It lies just north-west of the Finsteraarhorn, the main summit of the range.

Because the Lower Grindelwald and Unteraar glaciers drain into the Aar and hence the Rhine and North Sea, whilst the Fiescher glacier drains into the Rhone and hence the Mediterranean Sea, the Sidelhorn lies on the European continental divide.

[2] Administratively, the summit is shared between the municipalities of Grindelwald, to the north-west, Guttannen, to the north-east, and Fieschertal, to the south.

[2] The mountain was named after the Swiss geologist and explorer Louis Agassiz.