Imbruglia, 28, and Johns, 24, wed at the Thala Beach Lodge on the Australian northeast coast.
Her musical career took off with her chart-topping single "Torn" from the multi-platinum-selling 1997 album "Left of the Middle."
In 2003, Imbruglia starred in the comedy "Johnny English," a successful international film.
Johns' debut album, "Frogstomp," released in 1995 by his grunge band, sold more than 1 million copies. Silverchair has received critical acclaim for their follow-up albums, including "Diorama, Neon Ballroom and Freak Show."
In what has become common practice, the newlyweds will sell one snapshot of their wedding with proceeds going to their favorite charity.