Here are Singapore hotels that offer dedicated personal-concierge / butler / personal-assistant services (short note on what each provides). Service levels often depend on room/suite category, so confirm with the hotel when booking.

• Raffles Hotel Singapore — legendary 24/7 butler service (Raffles “butler” program). (raffles.com)
• Raffles Sentosa (Raffles’ Sentosa resort) — villas/manors with private butlers. (dailytelegraph.com.au)
• The St. Regis Singapore — St. Regis “Regis Butler Service” (complimentary butler services for suite guests; e-butler options). (marriott.com)
• Capella Singapore (Sentosa) — dedicated “Personal Assistants” / Manor Culturists offering bespoke 24-hour service for manors/villas. (capellahotels.com)
• The Fullerton Hotel Singapore — Fullerton Suite and club guests have access to butler services. (fullertonhotels.com)
• The Ritz‑Carlton, Millenia Singapore — Club/elite offerings include personalized/butler-style service for suite/club guests. (ritzcarlton.com)
• Shangri‑La Singapore (Valley Wing) — butler service available in the Valley Wing suites. (shangri-la.com)
• Marina Bay Sands — extensive concierge services at the resort (retail concierge) and butler-style service for top-tier suites/residences. (marinabaysands.com)
• Mandarin Oriental, Singapore — dedicated in-house “MO Curators” / Haus 65 team who provide concierge/curation for suites and VIP guests (not a private butler for every room). (robbreport.hk)
• Four Seasons Hotel Singapore — multilingual concierge, plus bespoke in-room services (personal shopper / club concierge for executive guests). (fourseasons.com)

If you’d like, I can pull current suite categories that include butler/personal-assistant service, compare which hotels include that service as standard vs. only for top suites, or check availability/rates for specific dates.