Each is a Norris finalist for the first time.
Subban topped the league's defensemen with 11 goals and 27 assists. Letang finished second in the scoring race among defensemen despite missing more than a quarter of the season. He had five goals and 33 assists in 35 regular-season games and added a goal and two assists in the first three games of Pittsburgh's opening-round playoff series against the New York Islanders.
"I'm honored," Letang said Tuesday before Game 4. "It's a great accomplishment. I think it's a team thing.
"Been a long process. Went through some steps. You need to play in every situation every night. Getting points is a way to see it."
Suter of Madison, Wis., ranked second among players at his position in assists (28) and third in points (32).
Members of the Professional Hockey Writers' Association submitted ballots at the end of the regular season. The winner will be announced during the Stanley Cup finals.
The finalists for the Vezina Trophy for top goalie will be announced Wednesday.