Here are Singapore hotels (city and Sentosa) known for on‑site kids’ clubs or regularly supervised children’s programmes — short notes on what they offer and typical age / booking points. I included official or reliable sources so you can confirm current hours, fees and sign-up rules directly with the hotel.

• Shangri‑La, Singapore (Orchard) — “buds by Shangri‑La” indoor play space plus an outdoor water playground (Splash). Parents may drop children aged 4+ for supervised sessions (children under 4 must be accompanied); activity classes (bake, crafts, themed sessions) are available for a fee. (shangri-la.com)

• Shangri‑La’s Rasa Sentosa Resort & Spa (Sentosa) — Cool Zone with Toots Club (supervised drop‑off for ages ~5–12), Mini Toots for toddlers (parent‑accompanied), daily themed activities, water play and big treehouse slide. Great option if you want beach + full kids programme. (shangri-la.com)

• Capella Singapore (Sentosa) — “Little Stars” family programme with supervised kids’ activities/workshops, cultural and culinary kids’ sessions and occasional kids’ camps; many family packages include organised children’s activities. (capellahotels.com)

• The Ritz‑Carlton, Millenia Singapore (Marina Bay) — “Ritz Kids” programme and a dedicated kids playroom/play areas with craft‑led activity sessions (welcome kit, activity book); the hotel runs regular supervised kids’ sessions and themed experiences. Check specific days/hours (some playroom hours are limited). (ritzcarlton.com)

• Marina Bay Sands (Marina Bay) — extensive family‑focused programming and curated family packages (family suites, kids’ adventure packs, attraction access and organized family experiences). While it’s an integrated resort rather than a traditional “kids club,” MBS runs many supervised family activities and event programmes. (marinabaysands.com)

• Hard Rock Hotel Singapore / Resorts World Sentosa hotels (Sentosa) — Hard Rock’s Roxity (Roxity Kids Club™) style supervised kids’ club offerings and RWS as an island resort offers multiple family programmes and attractions (Adventure Cove, Universal Studios), with hotel‑run kids activities. (hotel.hardrock.com)

• Sofitel Singapore Sentosa Resort & Spa — family‑friendly resort with kids’ programming, kid menus and school‑holiday activities; family offers and children’s events are regularly promoted. (Good for younger kids and a quieter Sentosa beach setting.) (sofitel-singapore-sentosa.com)

Quick practical notes (things families commonly need to check)

• Age limits, supervision rules and drop‑off policies vary widely (some clubs allow unattended drop‑offs 4–5+, others require parents for younger kids). Always confirm current age cutoffs and staffing ratios with the hotel.
• Some activities are complimentary for in‑house guests; others (special workshops, camps, mealtimes) usually carry extra fees and require advance booking.
• Hotels often run expanded kids programmes during local school holidays — book early for those dates.
• If you need babysitting (in‑room childcare), most large hotels can arrange vetted babysitters for an additional charge; request this in advance.

If you’d like, I can check current kids‑club hours, age rules and fees for any of these properties (or narrow options by area, budget or travel dates) and pull the direct hotel pages or package details.