Big Cone is a geyser in the West Thumb Geyser Basin of Yellowstone National Park in the United States.

Big Cone is a 7 metres (23 ft) wide sinter cone that rises from Yellowstone Lake about 7 metres (23 ft) from the shoreline. The vent of the cone is 80 centimetres (31 in) wide.^[1] At times of increased water level in the lake, the cone may be submerged completely.^[1][3] Big Cone is known to undergo rare eruptions 1 foot high or less.^{[citation needed]}