The CD, which was released six weeks ago, features the vocal talents of Idina Menzel, Kristen Bell, Josh Gad and Jonathan Groff.
The film was No. 1 at the box office last weekend.
"To date, the album has sold more than 500,000 units and will be certified gold shortly," the record label said in a news release. "Disney's last animated film and soundtrack to achieve simultaneous No. 1s was 'The Lion King' in 1994."
Rounding out the top tier are One Direction's "Midnight Memories" at No. 6, Luke Bryan's "Crash My Party" at No. 7, OneRepublic's "Native" at No. 8, the "Now 48" compilation album at No. 9 and Imagine Dragons' "Night Visions" at No. 10.