Defenceman (defenseman in American English) is a hockey player position on the ice whose responsibility is primarily defence. To shorten the name and to give consideration to the rising number of female players, the position is sometimes referred to as just "defence". Compared to forwards defencemen are generally slower and somewhat less agile. Usually, they have stronger shots.

In regular play there are two defencemen and three forwards on the ice along with the goaltender.

Defencemen are generally divided into two rough groups. A "stay at home" defenceman is primarily a defender who takes few risks but does not score much. An offensive defenceman is one that does jump into the play and scores more often but this tactic tends to lead to more breakaways by the other team.

The greatest NHL defenceman is often considered to be Bobby Orr who surprisingly managed to win scoring titles while playing defence.

Each year the NHL presents the Norris Trophy to the best defenceman.