Kimbrel, 23, won the National League's award in a unanimous decision, receiving all 32 first-place votes cast by two writers in each league city. He was the 10th NL player to win the award unanimously and the 17th overall.
Hellickson joined teammate Evan Longoria to become the second player in Tampa Bay team history to be recognized as the American League's top rookie. He received 17 of 28 first-place votes for 102 points. Angels first baseman Mark Trumbo received five first-place votes and finished second with 63 points. Royals first baseman Eric Hosmer was third with 38 points and Yankees right-hander Ivan Nova was fourth with 30.
The annual awards were voted on by the Baseball Writers' Association of America. Freddie Freeman, a teammate of Kimbrel, finished second in the NL voting, receiving 21 second-place votes and 70 points. He was followed by Phillies pitcher Vance Worley with 40 points. Nationals catcher Wilson Ramos, rescued this past weekend two days after being kidnapped in Venezuela, appeared on four ballots and finished fourth.
2011 AL ROOKIE OF YEAR VOTING
Kimbrel, who set a Major League record for saves by a rookie with 46, was the favorite for the award. His saves total led the NL, and he finished with a 2.10 ERA and 127 strikeouts in 77 innings for Atlanta, which narrowly missed out on the playoffs after a late-season slide that culminated with a blown save by Kimbrel on the final night of the regular season.
"I can't say it's something that I'll get over, but it's something that's going to push me and something that's going to make me strive to do better next year," Kimbrel said. "From a workouts standpoint, I'm going to do everything the same. My body felt good through the season. I felt like the workouts I did last offseason were very beneficial to this year.
"As for throwing, I'm not going to start throwing until about January. Last year, I started throwing a little bit earlier because going into Spring Training, I was fighting for a job and had to come in to prove myself. This year, I'm going to start a little bit later. I did learn that the season is long and you do throw a lot.
"Having a short memory is something you have to have as a closer or a relief pitcher. The way I think is, 'I'm going to get over it, but I'm not going to forget it.' I'm going to remember what I did wrong and try to fix it."
Hellickson, 24, was a workhorse in a young Tampa Bay rotation that helped fuel the Rays to a late-season surge and into the playoffs via the AL Wild Card. He was 13-10 with a 2.95 ERA, ranking eighth in the league in ERA and striking out 117 hitters in 189 innings.
He became the 10th starting pitcher to win the AL award, only the second in the past 30 seasons, and the first since Detroit's Justin Verlander in 2006.
"I guess I was a little surprised," Hellickson said. "There was a handful of guys I think all had the same amount of chance to win. I felt like I had a good chance, but once I finally did hear my name, I was really happy."
Kimbrel is the first pitcher to win the NL award since Dontrelle Willis of the Marlins in 2003. It is just the fourth time since each league began honoring a player in 1949 that two pitchers have earned the honor in the same season; the others being Joe Black and Harry Byrd in 1952, Butch Metzger and Pat Zachry (co-winners in the NL) and Mark Fidrych in 1976, and Fernando Valenzuela and Dave Righetti in 1981.
"It definitely did surprise me, with the unanimous decision," Kimbrel said. "For my teammate Freddie, I expected it to be close. I definitely am surprised by that.
"I want to strive to be as good as I can be. I want to learn hitters the best I can. I want to be in the best shape I can, be in the best throwing shape I can. That's one thing I'm doing this offseason -- get back to that point where I can go into 2012 and have a better year than I had in 2011."
Kimbrel was terrific through the long summer -- he did not blow a save in 39 appearances spanning June 11-Sept. 8 and was named to the NL All-Star team by Giants manager Bruce Bochy as a replacement for San Francisco pitcher Matt Cain.
Additionally, Kimbrel was named the Major League Baseball Delivery Man and NL Rookie of the Month in August, before being recognized as the Sporting News' NL Rookie of the Year at the season's end.
2011 NL ROOKIE OF YEAR Voting
He notched his 40th save of the season on Aug. 23, tying him with Rangers closer Neftali Feliz, who set the rookie mark last year and was subsequently named the AL Rookie of the Year. Kimbrel set the record for himself with save No. 41 on Aug. 31 against the Nationals. He had three blown saves in the month of September but still led the league in saves, with his last of the season coming on Sept. 23 against the Nationals.
He and Freeman, the Braves first baseman who hit .282 with 21 home runs, were the third set of teammates to finish 1-2 in NL rookie voting. The others were Jack Sanford and Ed Bouchee of the Phillies in 1957 and Jerome Walton and Dwight Smith of the Cubs in 1989.
Hellickson, who was named Rookie of the Year by Baseball America, had his best month in May, when he was 4-1 with a 1.36 ERA and one complete game, earning the AL Rookie and Pitcher of the Month awards. The right-hander went 3-0 in July and 2-0 in September, as the Rays closed a nine-game deficit behind the Red Sox and captured the Wild Card berth.