The province is in the Nan River valley. About 45 kilometers north of the city of Uttaradit is the Queen Sirikit Dam, which created a 250 km² artificial lake. The Phi Pan Nam Range reaches the northwest of the province.
Most of the province was once covered with teak forests, then the major product of Uttaradit. The largest teak tree in the world is found at the Ton Sak Yai Park in the Luang Prabang Range. The 1,500-year-old tree measures 9.87 m in circumference and 37 m in height. Originally it was 48.5 m high, but it was damaged in a storm.