Vermont Route 100 (VT 100) is a north–south state highway in Vermont in the United States. Running through the center of the state, it travels nearly the entire length of Vermont and is 216.666 miles (349 km) long. VT 100 is the state's longest numbered highway of any type.

Vermont Route 105 (VT 105) is a 98.135-mile-long (157.933 km) state highway located in northern Vermont in the United States. The route runs from U.S. Route 7 (US 7) in St. Albans in the west to the New Hampshire state line in Bloomfield in the east. The road continues across the state line as Bridge Street, a short unnumbered New Hampshire state route to US 3 in North Stratford, New Hampshire. As it is not a New Hampshire state highway, the connection is signed with Vermont state highway signage, similar to how connections to Vermont state routes are indicated elsewhere in New Hampshire.