Here are the top beach / sea-view hotels in Colombo (and the nearby Mount Lavinia area), with a short note on what makes each one good for a beach stay:

• Mount Lavinia Hotel — classic beachfront hotel with direct sandy beach access, colonial character and ocean‑view rooms; best choice if you want to swim and stay right on a proper beach (in the Mount Lavinia suburb just south of central Colombo). (mountlaviniahotel.com)

• Galle Face Hotel — historic, luxury seafront hotel facing Galle Face Green; excellent sea views and heritage atmosphere (note: frontage is on the urban coastline/promenade rather than a long swimmable bay). (en.wikipedia.org)

• Shangri‑La, Colombo — large modern 5★ on One Galle Face with many sea‑facing rooms and high‑end facilities (pool, spa, restaurants); great for panoramic ocean views and a central location. (shangri-la.com)

• Taj Samudra Colombo — long‑running 5★ hotel opposite Galle Face Green with ocean‑view rooms and full luxury facilities; good for business/leisure with easy access to the promenade. (en.wikipedia.org)

• The Kingsbury Colombo — waterfront hotel at the end of Galle Face Marine Drive with ocean/harbour views, big pool and family facilities; a solid luxury option with coastal outlook. (thekingsburyhotel.com)

• Marino Beach Colombo — newer 5★/upscale option in Bambalapitiya a short walk from Bambalapitiya beach; modern rooms, pool and family amenities. (marinobeach.com)

• Cinnamon Grand / Cinnamon Lakeside area — Cinnamon Grand sits on Galle Road (close to the seafront) while Cinnamon Lakeside is lakeside (not a beach hotel) — Cinnamon Grand is a large, well‑located city hotel if you want quick access to the coast plus lots of dining options. (en.wikipedia.org)

• Hilton Colombo — centrally located near Galle Face and the World Trade Centre with some sea/harbour views; not a sandy‑beach hotel but convenient and comfortable for city travellers who want ocean vistas. (hilton.com)

Quick practical tips

• If you want to swim off the sand, Mount Lavinia is the best bet; central Colombo hotels mostly offer sea views/promenade access rather than long, swimmable beaches. (mountlaviniahotel.com)
• West‑coast beach season (best weather for swimming on Colombo’s coast) is generally November–April — check local forecasts/monsoon timing before you book. (thetimes.co.uk)
• For a mix of beach + city nightlife/dining choose Mount Lavinia or Marino for beach access, or Shangri‑La / Galle Face / Kingsbury for luxury city stays with ocean views. (mountlaviniahotel.com)

If you want, I can:

• Sort these by budget (cheap → luxury),
• Check availability and approximate nightly rates for specific dates, or
• Suggest the best option for families / couples / business travel.

(Which would you prefer?)