The 48-year-old from Calgary, who has missed six of his last eight cuts on the PGA Tour, went 65-69 in the final 36-hole qualifier that was delayed one day by rain.
Tommy Biershenk earned his first trip to the tournament as medallist of the qualifier.
Ames, meanwhile, will be the lone Canuck in the field. He tied for ninth in the 2004 tournament at Shinnecock Hills Golf Club in Southampton, N.Y.
He also recently qualified for next month's British Open, where he will again be the lone Canadian entry.
Other PGA Tour players who qualified for the U.S. Open on Tuesday were Joe Ogilvie, Joe Durant, Bill Lunde and Hunter Haas.
The qualifier at Germantown Country Club was delayed one day by heavy rain. Biershenk opened with a 67 and followed with a 66.
Ogilvie tweeted, "I don't often drink beer, but when I qualify for the US Open, I drink Dos Equis. Stay thirsty my friends."
Hunter Hamrick of Alabama, coming off a team loss at the NCAA championship over the weekend, earned a spot next week at The Olympic Club. His teammate wasn't as fortunate. Bobby Wyatt got into a 3-for-1 playoff but was eliminated quickly. Robert Castro earned the final spot over Kyle Thompson with a par on the fourth extra hole.
Among those who failed to qualify were David Duval, Justin Leonard and Lee Janzen, a two-time U.S. Open champion who rallied to beat the late Payne Stewart the last time the U.S. Open was held at Olympic Club in 1998.
In golf's version of the Civil War rivalry earlier Tuesday, Nick Sherwood of Oregon State outlasted Oregon's Daniel Miernicki in a playoff that went three holes to determine the final spot. Casey Martin, who fought for the right to ride a cart because of a severe circulatory disorder in his right leg, earned the other spot Monday night with a five-foot par on the last hole. Martin now is Oregon's golf coach.
It took two days to complete 11 qualifiers across the country because of the rain in Memphis. Nearly 800 players competed for 58 spots, and now attention turns to the alternate list.
The U.S. Open set aside five spots in case players not already eligible moved into the top 60 in the world ranking on Sunday. Spencer Levin, who lost a 54-hole lead at the Memorial, is at No. 61 and is playing the St. Jude Classic. Three other players in range of the top 60 — Johnson Wagner, Greg Chalmers and Memorial runner-up Rory Sabbatini — are not playing.
If no one moves into the top 60, the first five alternates would get into The Olympic Club. The alternate list was not expected until later in the week.