Great question — Sri Lanka’s southwest coast has some of the most dramatic ocean sunsets in the Indian Ocean, and several resorts are repeatedly chosen by couples specifically for their sunset backdrops. Below are top picks (by region), why they work for wedding ceremonies/photos at sunset, approximate wedding-size suitability, and practical tips. I’ve included sources you can check for venue/wedding details.

Top sunset-resort picks for weddings

1. Cape Weligama (Weligama / Mirissa)

• Why: Dramatic clifftop villas, terraced lawns and an ocean‑facing infinity pool give sweeping west/southwest views over Weligama Bay — ideal for cinematic sunset ceremonies and photos. Excellent private‑villa options for rehearsal dinners and bridal prep.(BrandRadar.org)
• Best for: Small-to-medium to large events (flexible spaces, villa buy-outs possible).
• Good to know: Close to Mirissa attractions (whale watching, Coconut Tree Hill) for guests staying on after the wedding.(BrandRadar.org)

2. Amanwella (Tangalle)

• Why: Quiet, small ultra‑luxury resort tucked into a palm‑fringed cove with a long infinity pool and a semi‑private beach — perfect for intimate sunset beach ceremonies and sunset dinner receptions with minimal crowds. Photographers love the clean lines and ocean horizon at golden hour.(Smartflyer.com)
• Best for: Intimate to medium ceremonies (up to a few dozen/one‑hundred guests depending on setup).
• Good to know: Very popular in high season — book early and confirm beach/torch/lighting options with the events team.(travelaurel.com)

3. Jetwing Lighthouse (Galle)

• Why: Iconic Geoffrey Bawa–inspired architecture on a rocky headland north of Galle Fort with terraced lawns and ocean‑edge views — classic sunset lawn ceremonies overlooking the sea. The hotel has established wedding packages and event lawns used for sunset vows.(cherishluxury.com)
• Best for: Small-to-large receptions (hotel banquet spaces plus lawns; weddings up to a few hundred are routinely handled).(marriage.market)

4. The Fortress Resort & Spa (Koggala / Galle area)

• Why: Modern colonial/Portuguese‑inspired property with beachfront lawns, private spots for sunset ceremonies and pool/restaurant terraces that photograph beautifully at golden hour. The resort markets itself specifically for sunset beachfront weddings.(fortressresortandspa.com)
• Best for: Medium sized weddings (50–200 guests), with on‑site wedding planning services.(cvent.com)

5. Jetwing Saman Villas (Bentota)

• Why: Boutique cliffside property perched over the sea between two beaches; strong sunset vantage points from the cliff terraces and private pavilion settings — intimate, very photogenic.(en.wikipedia.org)
• Best for: Intimate to medium ceremonies (villa/resort buy‑outs for private events possible).

Other notable sunset-friendly options

• Cinnamon Bentota Beach / Jetwing Blue (Negombo) — convenient if many guests fly via Colombo; several beachfront lawns for sunset vows.(marriage.market)
• Anantara / Anantara Peace Haven (Tangalle area) and some luxury properties in Tangalle/Kamburupitiya — cliff/jungle‑meets‑ocean options for dramatic sunsets and larger events.(cinemotionphoto.com)

When to plan (season & weather)

• Southwest‑coast best time: November–April (dry season, calm seas and clear skies — ideal for reliable sunsets and beach ceremonies). High season is December–March (book early). Avoid May–October (southwest monsoon brings heavier rain and rough seas on the south/west coast).(traveldojo.com)

Quick practical tips for a sunset wedding in Sri Lanka

• Sunset time: Check local sunset times for your wedding date (roughly 5:30–6:30pm depending on season). Plan ceremony to end ~10–15 minutes before sunset for classic golden‑hour photos. (Local sunset times vary by date.)
• Backup plan: Always confirm an indoor or covered back‑up in case of unexpected rain; many hotels provide a wet‑weather plan.(cvent.com)
• Permits & local regs: If you want religious or public‑space elements (e.g., ceremony on a public beach or near Galle Fort), check local permits. Resorts usually handle permits, drummers, etc., if you use their wedding team.(tripadvisor.co.uk)
• Guest logistics: South/west coast travel times from Colombo airport are 1.5–3 hours by road depending on traffic — plan group transfers and accommodation blocks accordingly.(littleemperors.com)
• Photographer recommendations: Sunset lighting is short — ask your photographer for a ceremony timeline that captures pre‑sunset vows, the moment the sun dips, and immediate golden‑hour portraits.

If you’d like, I can:

• Narrow these to resorts that match a guest count (intimate 20–50 / medium 50–150 / large 150+), or
• Produce a short shortlist with ballpark pricing, sample wedding packages, and direct contact pages for each resort (I can fetch current wedding packages and availability for specific dates).

Would you like me to narrow by guest size or preferred region (e.g., Mirissa/Tangalle vs. Galle/Bentota)?