Johnson added a second major championship title at the 2015 Open Championship conducted by The R&A on the Old Course at St. Andrews, defeating Marc Leishman and Louis Oosthuizen in a three-hole aggregate playoff. Previously, the Drake University alum joined 1955 U.S. Open champion Jack Fleck as the only Iowa natives to win a major when he claimed the 2007 Masters. Johnson has earned 26 wins since turning professional in 1998, including 12 on the PGA Tour. He has been a member of five USA Ryder Cup teams and four U.S. Presidents Cup teams. In the final round of the 2014 U.S. Open at Pinehurst Resort & Country Club's Course No. 2, Johnson recorded the 44th hole-in-one in championship history.
U.S. Open Record
| Year | Site | Scores | To Par | Finish |
| 2018 | Shinnecock Hills Golf Club | 73-73-72-70--288 | +8 | T-12 |
| 2017 | Erin Hills | 71-74-68-74--287 | -1 | T-27 |
| 2016 | Oakmont Country Club | 71-69-71-71--282 | +2 | T-8 |
| 2015 | Chambers Bay | 72-72-78-73--295 | +15 | T-72 |
| 2014 | Pinehurst Resort & C.C. (Course No. 2) | 71-74-72-72--289 | +9 | T-40 |
| 2013 | Merion Golf Club | 74-77 | +11 | MC |
| 2012 | The Olympic Club | 77-70-73-71--291 | +11 | T-41 |
| 2011 | Congressional Country Club | 71-69-72-74--286 | +2 | T-30 |
| 2010 | Pebble Beach Golf Links | 72-77-78-79--306 | +22 | T-77 |
| 2009 | Bethpage State Park (Black Course) | 75-72 | +7 | MC |
| 2008 | Torrey Pines (South Course) | 76-74 | +8 | MC |
| 2007 | Oakmont Country Club | 76-74-76-74--300 | +20 | T-45 |
| 2006 | Winged Foot Golf Club (West Course) | 73-77 | +10 | MC |
| 2005 | Pinehurst Resort & C.C. (Course No. 2) | 74-75 | +9 | MC |
| 2004 | Shinnecock Hills Golf Club | 70-73-75-80--298 | +18 | T-48 |