The crash took place in New Haven County around 8:30 p.m. near Exit 23 on I-84 in Waterbury.
According to state police, both vehicles were traveling westbound when a Chevrolet Silverado driven by Fairfield County resident Zachary James Carlson, of Danbury, failed to slow down due to traffic and struck the rear of the tractor-trailer.
Carlson died from his injuries at the scene, police said.
The tractor-trailer driver, a 62-year-old Worcester, Massachusetts resident, was transported to St. Mary's Hospital by Trinity EMS for evaluation.
Both vehicles were towed by Karas Motors.
The case is currently under investigation.
Anyone who may have observed the accident or who may have any information is asked to contact Trooper Tyler Paustian at 203-267-2200.
Click here to follow Daily Voice Trumbull-Monroe and receive free news updates.