The Department of Health and Human Services confirmed the third death, that of an 89-year-old woman.
The department said 140 cases of Legionnaires' have been confirmed in 19 North Carolina counties and "multiple states." It says in addition to the three deaths, 94 people have been hospitalized.
The agency said the cases are connected to people who attended the Mountain State Fair last month in Fletcher.
It said testing found Legionalla bacteria in one water sample at the fair and those who were diagnosed with the disease may have walked by the hot tub displays.