0001508655 2025-07-30 2025-07-30 false 0001508655 8-K 2025-07-30 Sixth Street Specialty Lending, Inc. DE 001-36364 27-3380000 2100 McKinney Avenue Suite 1500 Dallas TX 75201 (469) 621-3001 false false false false Common Stock, par value $0.01 per share TSLX NYSE false