Here are the main 5‑star (or widely listed luxury) beachfront resorts in Bentota, Sri Lanka, with a short note for each:

• Cinnamon Bentota Beach — Classic Geoffrey Bawa–designed beachfront hotel, operated by Cinnamon Hotels; fully on Bentota beach. (en.wikipedia.org)

• Taj Bentota Resort & Spa (Vivanta by Taj was rebranded previously) — seafront luxury resort on Bentota’s shoreline, part of the Taj/Indian Hotels Group portfolio. (thetimes.co.uk)

• Centara Ceysands Resort & Spa Sri Lanka — beachfront/riverfront resort at the Bentota area (often listed as a luxury/5‑star property). (makemytrip.global)

Notes:

• Some nearby luxury properties (for example Anantara Kalutara) sit very close by on the southwest coast but are in Kalutara rather than Bentota proper; if you’re open to a short drive, they’re worth considering. (anantara.com)
• I can check current availability, rates, or show exact locations and contact links for any of these — tell me which ones you want pricing or booking info for.