"Frozen," which features the Oscar-winning song "Let It Go," sold another 115,000 copies last week, bringing its cumulative U.S. sales to 2.5 million, according to figures from Nielsen Soundscan.
Last week, "Frozen" ousted the soundtrack of Walt Disney Co's 1994 movie "The Lion King" to become the animated film soundtrack with the longest run at the top of the Billboard 200 chart.
Billboard said the "Frozen" soundtrack is the first album to cross 2 million in 2014. Beyonce's self-titled album is the second-biggest seller with 648,000.
Five new albums entered the Billboard 200 top 10 this week.
Rapper Future, who performed with hip hop duo Outkast at their reunion this month at the Coachella Valley Music and Arts Festival, landed at No. 2 with "Honest," selling 53,000 copies.
Australian rapper Iggy Azalea debuted at No. 3 with "New Classic," while indie rockers Neon Trees clocked in at No. 6 with "Pop Psychology."
The latest compilation from the cast of ABC's country music drama "Nashville" landed at No. 8, while Christian music group Bethel Music was No. 10 with "You Make Me Brave."
For the week ending April 27, overall album sales totaled 4.3 million copies, down 5 percent from the comparable week in 2013, Billboard said.