Encore: Movie Partners Sing Broadway, a collection of show tune duets featuring Hugh Jackman, Jamie Foxx and others, is her seventh number one album in the UK.
Encore recorded 20,000 combined sales, the Official Charts Company said.
In the singles chart, The Chainsmokers go top with Closer, the DJ duo's collaboration with US singer Halsey.
The Chainsmokers, aka Andrew Taggart and Alex Pall, said they were "beyond grateful at all the support from our UK fans".
"As a relatively new artist, it means a lot to us and gives us a lot of confidence in the music we have coming up," they said,
DJ Snake and Justin Bieber's Let Me Love You remains at two for the fourth straight week, one place above last week's number one record.
After five unassailable weeks in pole position, Cold Water - from Major Lazer and featuring Justin Bieber and MÃ˜ - drops to number three.
Calum Scott's Dancing On My Own and Twenty One Pilots' Heathens are non-movers at four and five respectively.
Twenty One Pilots occupy the same spot in the album chart, thanks to the US duo's fourth album Blurryface jumping six places to five.
The remainder of the top five is made up of Frank Ocean's Blonde at three, and Dolly Parton's Pure and Simple at four.
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A victim is taking legal action to force an independent inquiry with power to compel witnesses and the security services to hand over documents.
Gary Hoy was abused by two men who were subsequently convicted.
There have been allegations that a paedophile ring at Kincora was linked to the British intelligence services.
The government has so far refused calls for the abuse scandal at the Belfast home to be included within the scope of the inquiry established by Home Secretary Theresa May and headed by New Zealand judge Lowell Goddard.
The government has said that as child protection is a devolved matter, the right place for the Kincora allegations to be examined is Northern Ireland's Historical Institutional Abuse Inquiry, which has been sitting in Banbridge.
The victims of Kincora claim the Northern Ireland inquiry lacks the powers to compel evidence or witnesses from government agencies.
Amnesty International, which is supporting the victims' legal challenge, says two military intelligence officers have alleged that the security services blocked police investigations into the child abuse at Kincora in the 1970s.
The judicial review is expected to last several days.
Three senior care staff at Kincora were jailed in 1981 for abusing 11 boys.
At least 29 boys were abused at the home between the late 1950s and the early 1980s.
One of the men who was later convicted, William McGrath, is believed to have been an MI5 agent.

The 36-year-old was taken to a London hospital in a critical condition at about 03:45 after he became unwell at an address in Carshalton Road, Mitcham.
He died in hospital shortly after 07:00 GMT and his next of kin have been informed.
A police spokesperson said they were treating the death as "unexplained" and enquiries at the home were ongoing.
It is not believed that any other person was involved.
The spokesperson added that there was "no evidence to suggest that the incident is linked to extremism or terrorism".
Surrounding roads were closed as emergency services including fire engines carrying specialist chemical detection equipment attended the scene.
However, these have since reopened.
Glory, Britney Spears' latest release, has been beaten to the top of the UK album chart by the 35th studio album from US music veteran Barbra Streisand.
[NEXT_CONCEPT]
A judicial review has begun over the decision to exclude the former Kincora boys' home in east Belfast from a child abuse inquiry being held at Westminster.
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A man has died after he "came into contact with chemicals" at a house in south London, police said.