Michael Dawson (Harold Perrineau) was a construction worker who was one of the survivors from the central section of Oceanic 815 on "Lost." He was returning from Australia with his son, Walter (Malcolm David Kelley), of whom he had just gained custody after 10 years apart. Walter's mother had died and her husband requested that Michael take custody of him. Also on the flight was Vincent, Walt's pet labrador.
Michael initially had trouble bonding with Walt. This changed when they worked together to build a raft. When it was completed, Michael, Walt, Jin (Daniel Dae Kim) and Sawyer (Josh Holloway), attempted to escape the island, but were attacked by "The Others" and Walt was captured before the raft was destroyed.
When Michael found himself back on the island, he met the survivors of the tail section of Oceanic 815 and led them back to the camp. He became obsessed with rescuing Walt and getting him to safety. After receiving a message on the computer at the Swan station, he attempted a solo rescue and was captured. On his return to the camp, he shot Ana Lucia (Michelle Rodriguez) and Libby (Cynthia Watros) during a rescue of Ben Linus (Michael Emerson). He also arranged for "The Others" to capture Jack (Matthew Fox), Kate (Evangeline Lilly) and Sawyer. This was part of his bargain for the release of Walt, and they were both allowed to escape the island on a motorboat.
Michael returned to Manhattan with Walt, but his guilt led him to become suicidal and estranged from his son. In an attempt to redeem himself, he worked undercover on the Kahana and was there when the C4 bomb was discovered. He used liquid nitrogen to slow down the battery and allow the Oceanic 6 to escape before he was killed in the explosion.
After his death, Michael's spirit remained on the island and he tried to communicate through Hurley (Jorge Garcia) to help his friends. His voice could sometimes be heard among the whispers.
"You're wasting your time, man. If you pick the lock on a Halliburton, I'll put you on my back and fly us to L.A."
"It doesn't matter what I know; I built it! Maybe you are the wrong guy to go on the raft."