Bulaga played left guard in his true freshman year in 2007, and was a starter by mid-season. He was named to Sporting News′ Freshman All-Big Ten team. In 2008, he made the move to left tackle, and he started every game at that position for the Hawkeyes. He earned a second team All-Big Ten selection by the coaches and a second team Sophomore All-American selection by College Football News.

In 2009, Bulaga was listed at number three on Rivals.com′s preseason offensive tackle power ranking. He was also named to the 2009 Outland Trophy watch list.

After missing three games with a thyroid disease, Bulaga started all of the remaining games for the Hawkeyes, including their 24–14 win over the Georgia Tech Yellow Jackets in the 2010 Orange Bowl. He was named the Big Ten’s offensive lineman of the year for 2009.

On January 6, 2010, Bulaga released a statement about his intentions to forgo his final season of college and enter the 2010 NFL Draft.

Bulaga was selected in the first round (23rd overall) by the Green Bay Packers in the 2010 NFL Draft. He began the 2010 season as a back-up offensive lineman before getting his first start in the fifth week against the Washington Redskins. He went to start every game for the rest of the season, eventually being named to the NFL All-Rookie team. At 21 years, 322 days, Bulaga became the youngest player to start in a Super Bowl. Bulaga and the Packers defeated the Pittsburgh Steelers by a score of 31–25 in the Super Bowl.

During the 2012 NFL season, Bulaga injured his hip and in November was placed on season-ending injured reserve. The Packers decided to shift him over to the left tackle slot for the 2013 NFL season.

Bulaga suffered a torn anterior cruciate ligament (ACL) during training camp workouts on August 4, 2013. He missed the entire 2013 season.

In 2014, Bulaga had one of his finest seasons. Despite suffering an injury in week 1 to the Seattle Seahawks, he started and played in 15 of 16 games. Bulaga was instrumental in the offensive line giving up its fewest sacks (30) since the 2007 season and helped propel Eddie Lacy toward his second consecutive 1,000-yard rushing season.

On March 10, 2015, Bulaga and the Packers agreed to a 5-year deal, worth just under $7 million per year. On November 29, 2015, Bulaga was sidelined with an ankle sprain. He was later declared inactive for Week 13 against the Detroit Lions.

During Monday Night Football against the Lions in Week 9, November 6, 2017, Bulaga was carted off the field with a left knee injury. The next day, it was revealed that his left knee was diagnosed with a torn ACL, putting Bulaga out for the rest of the 2017 season. He was placed on injured reserve on November 18, 2017.

On March 30, 2020, Bulaga signed a three-year, $30 million contract with the Los Angeles Chargers.