A spokesman confirmed the pregnancy.
Costello, 51, is touring with Allen Toussaint in support of their album, "The River in Reverse."
The veteran British rocker's songs include "Veronica," "Pump It Up" and "Alison." The 41-year-old Krall will release a new album this September.
With motherhood, Diana Krall finally content
Apr 1, 2009 2:00 am PDT
Between a new album, an upcoming tour, producing a record for Barbra Streisand, a marriage to Elvis Costello and 2-year-old twin boys, it's hard to imagine Diana Krall can relax these days. But her hectic juggling has led to what the jazz...
Jazz pianist Diana Krall: Not just Mrs. Elvis Costello
Mar 30, 2009 11:00 am PDT
Diana Krall may be Mrs. Elvis Costello now, but the Grammy winner is still her own woman when it comes to her career as a jazz musician, as well as a budding record producer for no less than Barbra Streisand. Yet Krall was never too far a...
Diana Krall to release Brazilian jazz record
Dec 8, 2008 10:00 am PST
Diana Krall describes her first record in three years as intimate, sensual and erotic. "I'm not coy single girl singing 'Peel Me A Grape.' I love that song but I don't love it for me any more," Krall, 43, said from her Vancouver, B...
Diana Krall bowls over Hollywood crowd
Aug 19, 2007 11:38 pm PDT
Seeing the great Diana Krall again, now that she's a mother, is a real kick in the head, as Dean Martin used to say. And the way she talked about maternity would have gone right over with the Rat Pack. "Been away for a while," she ...
Krall drafts Botti for string of summer dates
Apr 27, 2007 1:30 am PDT
Diana Krall will hit the road this summer in North America, with jazz trumpeter Chris Botti supporting on 18 of the 38 dates. Beginning June 8-9 at Yoshi's in Oakland, Calif., the Grammy Award-winning jazz singer will be touring to p...