Because the 2013 draft was filled with talented young linemen most of the tackles had to wait months, until after the draft, to get a deal done.
"He will be a great addition to the offensive line both on the field and in the meeting room," said General Manager Jeff Ireland, who also signed Florida Atlantic linebacker David Hinds after a tryout at the team's recently rookie mini-camp.
Quarterback Clay Belton and linebacker Rob McCabe, two undrafted rookies who were signed on Friday, were waived to make room for the new additions.
According to FoxSports.com Clabo's deal is worth $3.5 million with $1.5 million of the contract being guaranteed.
Clabo is expected to compete with Nate Garner and possible Will Yeatman for the starting right tackle spot in 2013. It is also possible John Jerry, a starting guard for two of the past three seasons, could be moved over to right tackle.
"I'm a pretty tough critic on myself and I don't feel like there has been any drop in my play," said Clabo, who played in a zone blocking scheme during his practice squad stint with the Broncos, and early in his career with the Falcons. "I always want to do well. I want to feel like I did the job that I was brought here to do; My biggest driving force is success."
Clabo's addition means Jonathan Martin is expected to man the left tackle spot, with rookie Dallas Thomas, the Dolphins' third-round pick, serving as his primary backup.
Clabo has played with Atlanta his entire career and has started every game since 2008. Clabo, a former Wake Forest standout who bounced around the NFL in 2004 before finding a home with the Falcons, was a Pro Bowler in the 2010 season.
The Falcons released Clabo earlier this offseason to create $4.5 million in salary cap space.
Clabo, who turns 32 in October, started 80 straight games in Atlanta and was the fifth-rated right tackle in the NFL during the 2012 season according to ProFootballFocus.com.
In 2012, Clabo allowed six sacks according to Stats Inc. Pro Football Focus recorded Clabo had given up seven quarterback hits and 23 quarterback hurries.
The Dolphins picked Clabo over former UM standout Eric Winston, who has played with Houston and Kansas City in his career and hasn't missed a start since 2007.
The Dolphins also worked out Bryant McKinnie, who re-signed with Baltimore, and Winston Justice last week. Winston wants a multi-year deal, and the Cowboys remain a possibility for this seven-year starter.
Clabo, who is listed at 6-foot-6, 329 pounds, said a couple teams expressed interest in him before the draft, but once they added a few rookies the interest cooled. The Dolphins and Cowboys called last week and put him through a workout.
"I'm not here to prove anything," Clabo said when asked about his age, which makes him second oldest player on the Dolphins' roster. "I'm here to play football, have a good time and win. If I play well we'll have a chance to do those things."