Short answer: Singapore has very few true “all‑inclusive” resorts (meals + drinks + most activities all bundled). Instead, most family-friendly resorts — especially on Sentosa — sell family packages that bundle breakfast (often dinner), kids’ club access or attraction tickets, and some activities. Below are the best options and what their family packages typically include (sources linked).

Top picks (family-focused packages on Sentosa and nearby)

• Shangri‑La’s Rasa Sentosa Resort & Spa — “Rasa Family Fun / Rasa Family Splash” packages. Usually include daily breakfast (2 adults + up to 2 children), daily buffet dinner (for family members) with unlimited soft drinks and selected house beverages, kids’ club access / children’s activities, sea sports (kayak/SUP/pedal boat) and access to nearby family beach club. This is the closest to an “all‑inclusive” style family package on the island. (shangri-la.com)

• Resorts World Sentosa (Festive Hotel / Hard Rock Hotel / Equarius / Hotel Michael) — multi‑attraction family packages that bundle hotel nights + breakfast + attraction tickets (Universal Studios Singapore, Adventure Cove / S.E.A. Aquarium or multi‑park passes) and dining vouchers. Great if you want park access bundled with your stay (not full board all‑inclusive). (rwsentosa.com)

• Sofitel Singapore Sentosa Resort & Spa — family packages (e.g., “Infinite Family Experiences”) that include daily buffet breakfast, dining credits, kids’ dining perks (kids eat free or heavily discounted at certain ages) and family experiences/activities. Useful for families who want meal credits + kids’ benefits rather than full all‑inclusive. (sofitel-singapore-sentosa.com)

• Amara Sanctuary Resort Sentosa — “Family Adventure Escapade” and similar family offers: commonly include daily breakfast for family, kid treats, and attraction/activity inclusions (e.g., MegaZip / Mega Adventure tickets, discounts at the resort’s restaurants). Good for active families who want included experiences. (sentosa.amarahotels.com)

• Capella Singapore — luxury family packages (Family Retreat / Manor Experience variants) with daily breakfast, curated family experiences, and resort credits or attraction passes on some offers. These are luxury stays that include experiences rather than standard full board all‑inclusive menus. (capellahotels.com)

Why you’ll see few strict “all‑inclusive” resorts in Singapore

• Most Singapore hotels sell packages that bundle breakfast + selected meals, kids’ activities or attraction tickets; fully all‑inclusive (covering all food, free‑flow drinks and most activities for one flat price) is uncommon here. If you search “all‑inclusive” listings for Singapore you’ll find only a small number of packaged options and many hotels using the term loosely for meal‑and‑activity bundles. (Compare hotel offer pages above and aggregated hotel lists.) (tripadvisor.in)

Quick booking tips

• Check the exact inclusions (which meals, beverage limits, number of children covered, age cutoffs) and any blackout dates or minimum‑stay requirements on the hotel’s offer page before booking. (Children’s policies and whether dinner/drinks are included vary by package.) (shangri-la.com)
• Watch for service charge and GST (tax) added to published rates — Singapore hotels usually add a 10% service charge + prevailing GST. (See hotel T&Cs on their offer pages.) (capellahotels.com)
• If you want true all‑inclusive (most meals + most activities + drinks in one price) you may need to look off‑island (Bintan / Batam / Bali), where traditional all‑inclusive beach resorts are more common.

If you’d like, I can:

• compare specific packages for your travel dates/family size (price and inclusions),
• or send a short shortlist filtered by budget (value / midrange / luxury).

(References: official hotel offer pages and Resorts World Sentosa package pages noted above.) (shangri-la.com)