Sula is a census-designated place (CDP) in Ravalli County, Montana, United States. The population was 37 at the 2010 census. The area was originally called Ross's Hole from Alexander Ross, a Hudson’s Bay Company fur trader who had traveled through the area in spring 1824. In 1889, settlers named the post office after Ursula (Sula for short) Thompson, purportedly the first non-Indian child born in Ross’s Hole.