Interstate 291 (abbreviated I-291) is a short Interstate Highway in the state of Connecticut that starts at I-91 at its junction with Route 218 in Windsor and ends at I-84 in Manchester. It serves as a northeastern bypass of Hartford. The official length of I-291 is 6.40 miles (10.30 km), including 0.38 miles (0.61 km) of the exit ramp to the merge with eastbound I-84.

I-291 is also known as the Vietnam Veterans Memorial Highway for its entire length.

Heading east from I-91, I-291 has a partial interchange with Route 159, then goes across the Connecticut River on the Bissell Bridge. Originally constructed in 1957, the Bissell Bridge charged a toll until 1988 when the bridge was reconstructed. It has an interchange with US 5 in S. Windsor and ends at I-84 in a complex interchange that also includes ramps for US 6, US 44, and I-384.

The current I-291 is only the northeastern arc of what was originally planned as a three-quarter beltway around Hartford. From Windsor, I-291 would have continued to cross I-84 again in Farmington, and end at I-91 in Rocky Hill. While the remainder of I-291 was cancelled amidst environmental concerns, those two interchanges were built as part of I-84 and I-91 construction, and stood unused for over 20 years as ramp stubs. Half of the stack interchange at I-84 was eventually placed in service when Route 9 was extended to run along a portion of the I-291 right of way south of I-84 in 1992. The I-91 ramp was demolished in 1999 during expansion of I-91. The northernmost two miles (3 km) of the Route 9 expressway follows the original path of the southwest segment of I-291 from I-84. Route 9 currently serves as the southwest quadrant around Hartford leaving only the northwest section of I-291 unbuilt.

Route 218 is a 4-lane divided arterial route serving what would have been the northwest quadrant of the I-291 beltway. Over the years there have been discussions of constructing a multi-lane surface road from the I-84/Route 9 Stack interchange to Route 218 to complete the northwest bypass of Hartford, but funding and potential impacts to the reservoirs that supply Hartford with much of its drinking water have prevented anything from being built north of I-84. With the cancellation of the northwest quadrant of I-291, all travel between locations north and west of Hartford must pass through the I-84/I-91 interchange in Downtown Hartford. The Connecticut Department of Transportation headquarters was built on land originally acquired for I-291 where it intersects U.S. Route 5 in Newington.

The entire route is in Hartford County.