Lysite (also Lysaght) is an unincorporated community in northeastern Fremont County, Wyoming, United States. It lies along local roads northeast of the city of Lander, the county seat of Fremont County. Its elevation is 5,276 feet (1,608 m). Although Lysite is unincorporated, it has a post office, with the ZIP code of 82642. The Bridger Trail passed near Lysite on its way north to the gold fields of Montana in the 19th century.
Public education in the community of Lysite is provided by Fremont County School District #24. The district has three campuses – Shoshoni Elementary School (grades PK-6), Shoshoni Junior High School (grades 7-8) and Shoshoni High School (grades 9-12).