DEBT - Schedule of debt (Details) € in Millions, $ in Millions	Sep. 30, 2025 USD ($)	Sep. 30, 2025 EUR (€)	Jun. 30, 2025 USD ($)
Debt Instrument [Line Items]
Short-term debt	$ 0.0		$ 0.0
Long-term debt	4,061.2
Finance lease obligations & other long term debt	8.1		9.7
Total debt	4,069.3		4,008.4
Less: Short-term debt and current portion of long-term debt	(2.7)		(3.5)
Total Long-term debt	4,066.6		4,004.9
Less: Unamortized financing fees and discounts on long-term debt	(44.7)		(49.4)
Total Long-term debt, net	$ 4,021.9		$ 3,955.5
Finance lease, liability, statement of financial position flag	Long-term debt, net	Long-term debt, net	Long-term debt, net
Senior Secured Notes | 2026 Dollar Senior Secured Notes due April 2026
Debt Instrument [Line Items]
Long-term debt	$ 350.0		$ 350.0
Senior Secured Notes | 2026 Euro Senior Secured Notes due April 2026
Debt Instrument [Line Items]
Long-term debt	820.3	€ 700.0	820.0
Senior Secured Notes | 2027 Euro Senior Secured Notes due May 2027
Debt Instrument [Line Items]
Long-term debt	586.0		585.7
Senior Secured Notes | 2028 Euro Senior Secured Notes due September 2028
Debt Instrument [Line Items]
Long-term debt	586.0		585.7
Senior Secured Notes | 2029 Dollar Senior Secured Notes due January 2029
Debt Instrument [Line Items]
Long-term debt	500.0		500.0
Senior Secured Notes | 2030 Dollar Senior Secured Notes due July 2030
Debt Instrument [Line Items]
Long-term debt	750.0		750.0
Line of Credit | 2023 Coty Revolving Credit Facility due July 2028 | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	$ 468.9		$ 407.3