Joe Dawson is a fictional character in the Highlander franchise, created for the live-action TV show Highlander: The Series. A marine who leaves active service after losing his legs during the Vietnam War, he finds a new calling by joining the order of Watchers, people who record the lives and actions of immortals who secretly live on Earth. His main assignment during the course of the show is to chronicle the life of protagonist Duncan MacLeod, an immortal swordsman born in the Scottish Highlands. When the Highlander learns about the Watchers, he meets Joe and the two eventually become friends. Joe Dawson is portrayed by actor Jim Byrnes.

Born in 1950, Joe Dawson later joins the United States Marine Corps and fights in the Vietnam War. His commanding officer is Andrew Cord, an immortal (though at the time, Dawson is unaware such people exist). In 1968, after seeing Cord shot, Dawson accidentally steps on a landmine that explodes. Cord, now healed from his injuries, carries Joe on his back for sixteen miles to the nearest field hospital. Joe tries to explain Cord saved him, but is told Cord is dead. Due to his injuries from the landmine, both of Joe's legs are amputated. He is sent home.

Unable to cope with the loss of his legs, Joe decides to commit suicide but is visited by a Watcher named Ian Bancroft, who tells him that some rare humans are born immortal due to an energy called the Quickening. These immortals can only die if beheaded and can take each other's energy and knowledge if one kills another. Because of this, several hunt each other in a secret Game of mortal combat, believing that the final survivor will win the Prize: the collected power and knowledge of all immortals who ever lived. "In the end, there can be only one." Bancroft is part of an organization called the Watchers who study and chronicle the lives of these immortals from afar and will one day reveal this secret history to the world once the Game has been won. Bancroft offers to recruit Dawson into the organization. Driven by a new purpose in life and realizing he owes his life to an immortal, Joe becomes a Watcher historian in 1968. Bancroft becomes Dawson's mentor and a close friend. Joe later becomes brother-in-law to James Horton, a high-ranking Watcher. Joe develops a close friendship with Horton and comes to love Horton's daughter Lynn.

Later becoming a field operative, Dawson watches over the immortal Roy Ferrer (1971–1974) and then Liza Grant (1975–1978). In 1979, he is assigned to watch Duncan MacLeod, an immortal Highlander born in 1592 and kin to the immortal warrior Connor MacLeod born decades earlier. When Duncan MacLeod makes his home in Seacouver, Washington with his lover Tessa Noël, James Horton buys a nearby bookshop Shakespeare & Co. and has Dawson manage it in order to provide him a cover. Dawson comes to admire and respect MacLeod, noting that the Highlander does not wish power, forges friendships with several immortals, and cares deeply for mortal humans and society, often helping friends and strangers whenever he thinks they are in trouble.

Unknown to Dawson, Horton comes to believe that immortals are abominations and none of them will be uncorrupted by power if they win the Prize, meaning humanity will suffer no matter who wins the Game. Determined that human society will not be ruled by any immortal, Horton leads a sub-group of likeminded Watchers who call themselves the Hunters. The group begins secretly hunting and executing immortals, eventually gaining the attention of Duncan MacLeod when they kill his friend, an immortal priest named Darius. Finding a recovered Watcher's journal among Darius' possession, Duncan learns of the organization and then meets Horton when the man attempts to kill another immortal friend, Hugh Fitzcairn.

Eventually, MacLeod comes across Joe Dawson. Secretive at first, Joe realizes MacLeod already knows about the Watchers and sees them as enemies. To prevent conflict, he admits his true identity and purpose to the Highlander. "I probably know more about you than you know about yourself… I could tell you the time and place you became immortal, the name of your first love. But that's not important. What is important is that you care about mortals and you don't kill for pleasure."

After Horton is exposed and expelled from the Watchers (though MacLeod initially believes he is dead), Dawson attempts to forge trust with the Highlander, openly informing him about his presence on various occasions. MacLeod is reluctant to trust at first, particularly after the recent death of his love Tessa, murdered by a mugger. As they slowly build a friendship, Dawson also befriends the Highlander's immortal apprentice Richie Ryan and his mortal friend and colleague Charlie DeSalvo, a martial artist who manages Duncan's gym and is unaware of the existence of immortals. At times, Dawson helps MacLeod by sharing Watcher information on other immortals, believing it serves the greater good if evil immortals are removed from the Game and secretly hoping the winner will be someone like the Highlander.

When Horton hunts immortals again, this time in allegiance with the evil immortal Xavier St. Cloud, MacLeod is furious that Joe lied about the man's death. Horton and his men then nearly kill Charlie DeSalvo while attempting to help St. Cloud kill MacLeod. Later, Horton attempts to flee again and Dawson shoots him. Horton falls into the water and Dawson tells Duncan, "We make mistakes... we clean them up." Horton later turns up alive and attempts to attack MacLeod psychologically through an agent masquerading as his dead love Tessa. Dawson prevents Horton from shooting MacLeod later and the Highlander finally kills the man. Dawson sees to the burial.