The extension is for five years and is worth $52.15 million with $22 million guaranteed, according to ESPN.com.
The University of Florida product is a four-year NFL veteran who started all but five of the Dolphins' games over a four-season span.
Pouncey played center for the 2011, 2012 and 2013 seasons, but played predominantly at right guard during the 2014 season.
He went to the Pro Bowl in 2013 and 2014.
- Will Green