The Islanders chose Tavares, an 18-year-old junior star with the London Knights, with the first overall pick ahead of 6-foot-6, 220-pound Swedish defenseman Victor Hedman, the top-ranked European prospect.
The Tampa Bay Lightning took Hedman and the Colorado Avalanche followed with forward Matt Duchene, the first three selection going as expected.
The Philadelphia Flyers made an early splash by acquiring All-Star defenseman Chris Pronger from Anaheim in a multi-player trade. The Ducks reacquired right wing Joffrey Lupul and received defenseman Luca Sbisa and two first-round draft picks.
Tavares, a 6-foot, 185-pound native of Oakville, Ont., led the Ontario Hockey League with 58 goals this season and broke Peter Lee's 33-year-old league record of 213 career goals.
Islanders GM Garth Snow kept the team's draft intentions a closely guarded secret right until he announced Tavares' name to the Bell Centre crowd as the team's fourth No. 1 pick overall in draft history, and the first since they made Rick DiPietro the first goalie selected first overall in 2000.
"Yeah, I had no idea, just like everybody else," Tavares said. "I didn't know what their decision would be but it was obviously a great moment for me, a special feeling."
Tavares' selection was immediately celebrated by Islanders fans, who were shown on the Bell Centre video scoreboard gathered for a team draft party at Nassau County Coliseum, the team's arena in Uniondale, N.Y.
"I didn't see it but I heard things and obviously they are really interested in having me, and I definitely have the support of the fans and the community that's huge," Tavares said. "I'm very thankful to be going there and I appreciate the opportunity to be part of Long Island. It's going to be great and I can't wait to get things going knowing where it's headed. It's going to be a great future for all of us."
The expansion Islanders chose Billy Harris No. 1 overall in 1972 and followed that up one year later by selecting Denis Potvin, a Hall of Fame defenseman who captained the team to four straight Stanley Cups from 1979-80 to 1982-83.
Hedman joins a Lightning squad that drafted center Steven Stamkos first overall last season.
"My goal is to play with the Tampa Bay Lightning next season," Hedman said. "I'm going to work hard this summer to make the team next year."
After Duchene was picked third by Colorado, his favorite team growing up, Atlanta selected center Evander Kane of the Vancouver Giants, followed by Los Angeles, which chose Brandon Wheat Kings center Brayden Schenn, the younger brother of Toronto defenseman Luke Schenn, who went fifth overall to the Leafs last year in Ottawa.
The embattled Phoenix Coyotes delivered the first surprise of the first round when they drafted Swedish defenseman Oliver Ekman-Larsson with the sixth pick.
Toronto GM Brian Burke was subjected to a chorus of boos from the Montreal Canadiens fans filling the upper reaches of the arena before he announced center Nazim Kadri, Tavares' Knights teammate, with the seventh selection.
Right wing Scott Glennie, Brayden Schenn's Brandon linemate, was chosen eighth by Dallas. Ottawa drafted 6-foot-5, 220-pound defenseman Jared Cowen of the Spokane Chiefs with the ninth pick, followed by Edmonton, which took Swedish center Magnus Paajarvi-Svensson to complete the top 10.