Her 15th studio album, Disco, topped the charts with 55,000 sales, meaning it has also scored the best opening week of any new release in 2020 so far.
It is her eighth number one, meaning she has overtaken Elton John, Cliff Richard and George Michael in the all-time chart leaderboard.
"I'm lost for words," said the star.
"Thank-you to everyone who has supported this album. I'm so touched that it's made its way to your hearts. I love it."
Only five other acts have topped the Official Chart across five consecutive decades: Paul McCartney, John Lennon, Paul Weller, Bruce Springsteen and David Gilmour.
The Beatles, Elvis Presley, The Rolling Stones and Bob Dylan have also landed chart-toppers across five decades, though not consecutively.