Kollóttadyngja is a volcano in Iceland. Situated in the Ódáðahraun lava-field at , its height reaches 1,177 metres, with a diameter of 6–7 km. The summit crater is 800 metres in diameter, but only about 20–30 metrees deep, and in its centre, there is a bowl of about 150 metres in diameter, with a depth of about 60–70 metres.