The Junior Iditarod Sled Dog Race, or Jr. Iditarod, is a 148- to 158-mile (222 km) sled dog race for mushers between the ages of 14 through 17, which is patterned after the 1,150-mile Iditarod Trail Sled Dog Race that is said to be 1,049 miles (1,688.2 km). The race is held outside Anchorage in the U.S. state of Alaska, and was the first long-distance race for juvenile mushers.

With the encouragement of “Go for it” Joe Redington, Senior, the Jr. Iditarod was established 1977 by Eric Beeman, Rome Gilman, Karl Clausen, Kenny Pugh, and Clarence Shockley, who were unable to compete in the Iditarod because they were less than 18 years of age. In October 1987, the Jr. Iditarod officially became part of the Iditarod Trail Committee, which manages the senior race.

The Jr. Iditarod race is designed as a long-distance race, as opposed to a “sprint, or speed race”, and is intended to help prepare younger mushers for the even longer Iditarod.

The race commonly runs from Knik for 69 miles (111 km) along the Iditarod Trail to the Yetna Station Roadhouse. Trail location may vary year to year depending on trail conditions and due to poor conditions locally has started and finished in the Willow as well as the Lake Louise areas. At the half way point mushers must care for their sled dogs and camp overnight for either 8 or 12 hours, before returning the following day. The first Jr. Iditarod had junior, kids 11 through 13 years of age and running 4 to six dogs, and senior divisions, kids 14 through 17 years running a maximum of 10 dogs. the junior division ran a total of 18 miles and 40 miles (58 and 64 km), for the senior class respectively. Senior mushers spent the night camping with their dogs at Mud Lake in the Big lake area. By the second year due to logistics, the two divisions were abolished, age was now 14 through 17, and the distance was increased to 90 miles (145 km) in 1978, and then to 120 miles (193 km) in 1979. Each team is composed of between 6 and 10 sled dogs, and is required to carry the same equipment as the competitors in the Iditarod.

The Jr. Iditarod is held in the weekend before the Iditarod. The winner of the junior event takes the honorary first position out of the chute during the ceremonial start of the longer race in Anchorage on the first Saturday in March, and leads the pack to the first “checkpoint.”

Jr. Iditarod mushers are mostly from Alaska, though the U.S. states of Minnesota and Montana Montana, Massachusetts, Ohio, Georgia, Washington, Pennsylvania, Yukon Territory, Canada, have been represented, and Thomas Krejci of Czechoslovakia became the first international competitor in 1992, also winning the Humanitarian Award that year.

In 2017, Katie Winrich was the first competitor to run the race to hail from Wisconsin. All mushers are between the ages of 14 and 18, and frequently train their own teams of sled dogs. A number of previous competitors have gone on to compete in the longer Iditarod, including Lance Mackey, Tim Osmar, Ramey Smyth, and Cim Smyth, to name but a few.