Ryder was drafted by the Montreal Canadiens in the 1998 NHL Entry Draft, 8th round, 216th overall. He hired hockey agent Thayne Campbell before signing with Montreal.
In the 2003–04 NHL season, he played in the NHL YoungStars Game. He was named the NHL Rookie of the Month for February 2004. He finished the season leading all rookies in points, powerplay points, shots, and goals. During the 2004–05 NHL lockout he played for Leksands IF of the second division of Swedish hockey. He reached 30 goals in back-to-back seasons after the lockout.
On April 7, 2007, he scored a natural hat-trick in the 2nd period against the Toronto Maple Leafs when the Canadiens were down 3–1. This was the most important game of the regular season since the Leafs, Canadiens, and the New York Islanders were vying for the last playoff spot in the Eastern Conference, and the game would determine which team would take the last playoff spot. Despite Ryder's effort, the Canadiens eventually lost the game 6–5.
On October 9, 2008, Ryder scored his first goal in a Bruins uniform in Boston's season opener against the Colorado Avalanche, a 5-4 Bruins victory. The goal coincidentally was Ryder's 100th career goal. He went on to score 27 goals in his first season with Boston as the Bruins clinched first overall in the Eastern Conference. Their first round matchup was with the eighth seeded Montreal Canadiens, Ryder's former club. He scored four goals in the series as the Bruins made quick work of Montreal, sweeping them in four straight games. Ryder was then held to only one goal during the Bruins seven game Conference semi-finals loss to the Carolina Hurricanes.
On July 1, 2011, Ryder signed a two-year, $7 million contract with the Dallas Stars. In the 2011–12 season, he recorded a career high 35 goals during his first season in Dallas.
During his second year with the Stars in the lockout shortened 2012–13 season, Ryder was traded back to the Montreal Canadiens, along with a third round pick in the 2013 NHL Entry Draft, in exchange for Erik Cole.
On July 5, 2013, Ryder signed a two-year, $7 million contract with the New Jersey Devils. Due to the Devils policy under Lou Lamoriello of numbers above 40 being prohibited, Ryder switched from wearing sweater 73 to 17 during his tenure with the club.
