The Roar singer shakes off Swift, a distant second with $80m, while Fleetwood Mac came a surprise third in the money league.
Katy Perry has beaten pop rival Taylor Swift to become the highest-earning woman in music this year, according to Forbes.
Perry, 31, earned $135m (£88m) in the past 12 months, compared with an estimated $80m for Swift, 25, the business publication estimated.
British-American rock band Fleetwood Mac came in a surprise third with $59.5m, though only two of its five current members are women – and Christine McVie only rejoined the band last year after a 15-year absence.
Perry’s earnings were boosted by a worldwide tour, Prismatic, as well as endorsement deals with beauty firms such as CoverGirl.
The Roar singer’s latest album Prism has sold four million copies worldwide since its release in 2013.
Shake It Off singer Swift ranked a distant second despite some 8.6 million in global sales for her hit album, 1989, and the start of a world tour.
Lady Gaga ranked fourth with $59m – a big fall from her 2011 peak of $90m when she grabbed headlines with outrageous stunts and costumes.
Last year’s top earner Beyonce slipped to fifth place with an estimated $54.5m.
Britney Spears ($31m), Jennifer Lopez ($28.5m), Miranda Lambert ($28.5m), Mariah Carey ($27m) and Rihanna ($26m) rounded out the top 10.
The 1970s veterans Fleetwood Mac pulled in over $1m per city on their 86-date, year-long On With the Show tour.
The Forbes list measures estimated pre-tax income from June 2014 to June 2015, and includes earnings from albums, tours, endorsements and other commercial deals.