The Canadian midfielder will remain with the club through 2014.
"Reaching a long-term agreement with Will Johnson is yet another milestone in the significant steps our organization has taken to keep our core group together as we compete in CONCACAF Champions League and pursue another MLS Cup title," said RSL manager Garth Lagerwey. "Will has been one of several critical figures in establishing RSL's competitive culture, and we look forward to seeing him in Claret & Cobalt for the longer term."
The versatile 23-year-old joined the club in August 2008 after stints at Heerenveen and De Graafschap in the Netherlands and has since been a regular for RSL, appearing in 63 matches and tallying four goals and four assists.
"I think I have a lot of good soccer years ahead of me, and I couldn’t be more thrilled to be spending the next four of them with Real Salt Lake," said Johnson. "I’ve found a home here in Salt Lake and a club with an atmosphere that I believe is a winning one. I have a lot in common with Jason [Kreis] and Garth [Lagerwey] in regards to what it takes to win, and obviously that’s my goal. I want to help take this club forward and spend the best years of my career here with Real Salt Lake."
Other highlights from Johnson's MLS career include a stunning strike against FC Dallas in October 2008 that eventually earned MLS Goal of the Year honors and a 45 minute cameo in Real Salt Lake's MLS Cup final victory over the Los Angeles Galaxy in the 2009 MLS Cup final.
For Canada, Johnson has represented his country throughout the youth levels and made his senior national team debut at age 18 in 2005, and has since earned 13 caps for the national team, but is without a goal.
Johnson's extension represents the latest move in a busy offseason for Real Salt Lake, who have also re-signed Alvaro Saborio and Paulo Jr., as well as trading for El Salvador international winger Arturo Alvarez after he was picked up by the Portland Timbers in the Expansion Draft.
The Salt Lake Tribune reports that RSL is looking to tie down defender Nat Borchers and goalkeeper Nick Rimando to contract extensions next.