Great — here are top family‑friendly luxury resorts across Sri Lanka that offer organised kids’ activities, family rooms/interconnects and child‑friendly facilities. I’ve picked options in different regions (south coast, southeast, cultural triangle) so you can match beaches or inland excursions.

1. Cape Weligama (Weligama / Galle area — southern coast)

• Why families love it: a nature‑inspired “Forest School” kids’ club with age‑grouped, device‑free programmes (2–15 yrs) — tree‑climbing, sand play, junior chef sessions, crafts and seasonal forest camps. Lots of family suites and interconnecting options, shallow family pool and supervised children’s activities. (resplendentceylon.com)

2. Anantara Peace Haven Tangalle (Tangalle / southern coast)

• Why families love it: dedicated kids’ and teens’ clubs (Joli Kids’ Club), babysitting on request, child menus and family villas with private plunge pools; property arranges family excursions (turtle watching, nature walks, surfing lessons and safaris nearby). Good for families who want a cliff‑top luxury stay with on‑site childcare. (anantara.com)

3. Amanwella (Tangalle area)

• Why families love it: ultra‑luxury boutique resort with interconnecting suites and family extras (cots, kids’ menus, babysitting); resort runs supervised activities for children (junior chef, beach play, surf lessons and nature/heritage trips) while offering tranquil spaces for parents. Best if you want very high‑end privacy plus family services. (mrandmrssmith.com)

4. Shangri‑La Hambantota (Hambantota / southeast coast)

• Why families love it: large resort with a proper Cool Zone Kids Club and Aqua Zone (waterslides, splash pad), supervised programmes for ages ~4–12, family pools, adventure‑style outdoor activities (trapeze, mini‑golf, nature trails) and lots of organised kids’ entertainment. Great choice if you want resort‑scale facilities and lots of on‑site kid options. (shangri-la.com)

5. Heritance Kandalama (Sigiriya / Cultural Triangle — inland)

• Why families love it: architecturally iconic resort set by Kandalama reservoir with family‑friendly facilities (kids’ activities, playground, pools), nature walks, easy access to Sigiriya and Dambulla excursions and organised family outings (birdwatching, safaris and cultural experiences). Good pick if you want luxury inland base for cultural/wildlife days with child‑focused programming. (thehotelguru.com)

Quick planning tips

• Regions: south coast (Weligama/Tangalle/Galle/Mirissa) = beaches, surfing and whale watching; southeast (Hambantota) = large resort complexes and protected family water parks; Cultural Triangle (Sigiriya/Dambulla/Kandy) = heritage, safaris and nature. Choose based on whether you prioritise beach time or cultural/wildlife day trips.
• Ages: resorts’ kids’ clubs often segment by age (2–5, 6–12, teens). If you need childcare for toddlers under 4, confirm supervised creche rules — some clubs require parent accompaniment for very young children.
• Family rooms: ask each hotel about interconnecting suites, extra‑bed policy and whether the first child stays free (policies vary by resort/season).
• Safety & seasons: Sri Lanka’s main beach season on the south coast runs roughly November–April (calmer seas/whale season). Check current sea conditions and kids’ swimming safety at each resort before booking.

Would you like these ranked by: (a) best for small kids (0–6), (b) best for teens, (c) best value luxury, or (d) help checking availability and sample family room rates for specific dates? I can look those up and compare options.