Belfast is an unincorporated area of Lassen County, California.

[1] It is located 5.5 miles (8.9 km) northwest of Litchfield,[2] at an elevation of 4134 feet (1260 m).

[2] It was expected that a railroad would be built through the Belfast townsite,[3] but this never happened.

Merrill did, however, successfully build an irrigation flume to aid in farming; in 1922, the Belfast area was subdivided into forty-acre plots in the hopes of reestablishing a farming community.

The Willow Creek Canyon in the Belfast area is an important archaological site, with rock structures and petroglyphs suggesting it was a major hunting ground to native peoples.