He was signed by the Jacksonville Jaguars as an undrafted free agent in 2005 after playing college football at Southeast Missouri State.

Connolly was signed to the New England Patriots' practice squad on September 13, 2007, where he spent the remainder of the season before being re-signed to a future contract on February 5, 2008.

He was a reserve for the team's Week 9 game, but returned to the starting lineup at right guard following a season-ending injury to Neal.

In a December 19, 2010 game against the Green Bay Packers, Connolly set the record for the longest kickoff return by an offensive lineman in NFL history, returning a squib kick 71 yards to set up a Patriots touchdown (the previous record was 48 yards by Mal Snider in 1969).

[6] On February 1, 2015, he was part of the Patriots team that won Super Bowl XLIX over the Seattle Seahawks, 28–24.

However, on July 16, 2015, Connolly retired, citing family stability, concussion injuries and winning the Super Bowl as contributing factors.