Geography thumb|left|Map of Olney Township, MN, 1914 According to the United States Census Bureau, the township has a total area of 35.5 square miles (91.8 km), of which 35.4 square miles (91.7 km) is land and 0.04 square mile (0.1 km) (0.08%) is water. The main geographic feature of Olney Township is the east branch of the Kanaranzi Creek, which extends through the northern sections of the township.
Geography thumb|left|Map of Olney Township, MN, 1914 According to the United States Census Bureau, the township has a total area of 35.5 square miles (91.8 km), of which 35.4 square miles (91.7 km) is land and 0.04 square mile (0.1 km) (0.08%) is water. The main geographic feature of Olney Township is the east branch of the Kanaranzi Creek, which extends through the northern sections of the township.