Hickey, who takes over for Jeff Ireland, will mainly be responsible for putting together the Dolphins roster this coming offseason—and possibly beyond if the Dolphins have a successful 2014 season.
But what do we know about Hickey other than the fact that he once worked across the state with the Buccaneers, and what can his history with the Buccaneers tell us about what he can do with the Dolphins?
Here's a look at everything you need to know about Miami's new general manager.
You're probably wondering why this slide has a picture of a Tulsa Golden Hurricanes helmet.
Good reason: Hickey, who's 43, graduated from the University of Tulsa in 1994. Prior, he graduated from Coffeyville Community College in Kansas.
After graduating from Tulsa, Hickey spent two years as an assistant coach at Blinn Junior College in Brenham, Texas (Carolina Panthers quarterback Cam Newton and Miami Heat center Chris Andersen also attended Blinn, according to their Wikipedia page).
Hickey left Blinn in 1996 to join the Tampa Bay Buccaneers as a pro personnel assistant in scouting. He was promoted to college scout in 1998, focusing mainly on the Midwest.
In 2004 with the hiring of Bruce Allen as Buccaneers general manager, Hickey was promoted once again, this time to director of college scouting.
His next promotion within the Buccaneers system would come in 2011, when he was named director of player personnel.
Hickey is married and has two children.
Biographical information courtesy of the Palm Beach Post.
Part of what will determine Hickey's success with the Dolphins (as well as his fate past 2014) is how well he can work with Miami Dolphins head coach Joe Philbin.
Hickey doesn't have the power to fire Philbin, meaning technically the two are equals.
Working together won't be too much of a problem. At least it shouldn't be as the two have a history together.
While Hickey was a scout with the Buccaneers in the 1990s, he was in charge of scouting the Midwest.
At the time, Philbin was an assistant at Iowa under Kirk Ferentz. Through Philbin's job as an assistant coach and Hickey's job as a scout, the two met around that time, according to the Miami Herald's Adam Beasley.
Fast forward to 2012, when the Buccaneers were looking for a head coach. One of the people interviewed for the job was Philbin. According to ESPN's Adam Schefter, that's the first time the two bonded.
The Buccaneers hired Greg Schiano that year, while Philbin accepted the job with the Dolphins.
Hickey has been in Tampa Bay for so long that he has worked under three general managers and four head coaches.
When Hickey started in Tampa in 1996, Rich McKay and Tony Dungy were hard at work building what would eventually be a Super Bowl winning team that had the likes of Warren Sapp, Derrick Brooks, John Lynch and Ronde Barber.
Hickey stayed on and was promoted under the team of Jon Gruden and Bruce Allen. It was under Allen that Hickey became Tampa Bay's director of college scouting.
Once Allen and Gruden were fired after the 2008 season, Hickey remained director of college scouting. It was 2011 when general manager Mark Dominik promoted Hickey to director of pro personnel.
When Dungy was asked about Hickey's hiring on Twitter, Dungy endorsed Hickey: "D. Hickey is a very good [football] man. Dolphins did well!"
To really look at Hickey's history as an executive, it really starts in 2011 when he accepted the job of director of player personnel.
At that post, Hickey oversaw the Buccaneers' draft as well as free agency, and that two-year span included some of the Buccaneers' most active free-agency periods.
Hickey excelled at finding early-round picks, dating back to 2011, when he drafted Adrian Clayborn in Round 1. Clayborn has started 35 games in his young career, netting 13.5 sacks, 72 tackles and five forced fumbles. The only games Clayborn hasn't started or played in were games he missed due to injury in 2012.
The 2012 draft was a good one for the Buccaneers, as they had two first-round picks. The first pick would be safety Mark Barron from Alabama. In two years with the Bucs, Barron has 176 tackles, two sacks, two interceptions and a forced fumble, and will be a centerpiece of the Buccaneers defense going forward.
Tampa Bay then traded into the first round to acquire running back Doug Martin. Martin struggled with injuries in 2013 as he played in only six games and gained 456 yards and scored one touchdown on 127 attempts.
Martin's rookie year showed plenty of promise, as Martin ran for 1,454 yards and 11 touchdowns on 319 attempts as a main cog in the offense.
That draft would also see the Bucs get outside linebacker Lavonte David in Round 2. In two seasons, David has 283 tackles, eight sacks and six interceptions.
The team's 2013 draft didn't feature a first-round pick, as it was traded to the New York Jets in exchange for Darrelle Revis. The Bucs used a second-round pick on cornerback Johnthan Banks, who had 49 tackles and three interceptions on the year.
In Round 3, Tampa Bay drafted Mike Glennon, who looks like he could pan out as its quarterback of the future after a strong showing in the latter half of his rookie year.
The Bucs have also been active in free agency, and have had their fair share of hits and misses. Vincent Jackson has been a signing that hit for the Bucs, while Carl Nicks and Eric Wright have been flops.
Overall, the Buccaneers have done a good job of amassing talent under Hickey, especially in the early rounds of the draft, where the Dolphins have had their issues under Ireland.
Hickey has shown himself to have a good eye for defensive tackles, corners and running backs, which are major needs on the Dolphins this offseason.
Why was Dennis Hickey hired in the end?
His record at acquiring talent in the draft had a lot to do with it, in fact, Per Omar Kelly of the Sun Sentinel, it was his experience in the draft that attracted Stephen Ross to Hickey:
His in-depth draft experience, and his history won Ross over. Sources say he was the most thorough candidate when it came to breaking down the draft process, especially when it involved gathering information on prospects.
Kelly reported that Hickey was also hired because of his ability to work as a team alongside Philbin and Dawn Aponte. While Hickey won't have the power to fire Philbin, he will work ahead of Aponte in terms of player personnel matters, and he will have final say on all roster decisions.
Hickey's experience with the draft is what got him into Davie, and if he's able to replicate some of his early-round draft success, he will help the Dolphins improve.
In the end, fair or not, it will be up to how the players play on the field that will determine Hickey's fate in Miami, which means Hickey, for better or for worse, is tied to Philbin.
It was a situation that many of the candidates in Miami didn't want to deal with, but Hickey felt comfortable enough with that arrangement to take the job.
Now let's see where he can take the Dolphins as they begin their lead-up to free agency and the draft.