v3.26.1
Cover
May 22, 2026
Cover [Abstract]  
Document Type 8-K
Amendment Flag false
Document Period End Date May 22, 2026
Entity File Number 811-24080
Entity Registrant Name FS Specialty Lending Fund
Entity Central Index Key 0002065812
Entity Tax Identification Number 33-4638504
Entity Incorporation, State or Country Code DE
Entity Address, Address Line One 3025 JFK Boulevard, OFC 500
Entity Address, City or Town Philadelphia
Entity Address, State or Province PA
Entity Address, Postal Zip Code 19104
City Area Code 215
Local Phone Number 495-1150
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Emerging Growth Company false