Here are well-regarded luxury resorts across Sri Lanka that offer private/standalone villas (or villa‑style pavilions) designed for two — good for couples, honeymoons or romantic getaways. I’ve listed the property, the region, the villa type that’s suitable for two, and a short note.

• Amanwella — Tangalle / South Coast. Pavilion-style suites and low‑rise pavilions with private terraces and very intimate, secluded beachfront settings (ideal for couples). (brandradar.org)
• Cape Weligama — Weligama / South Coast. One‑bedroom Prestige/Grand Villas and private‑pool villa categories (many designed and marketed specifically for couples/honeymooners). (brandradar.org)
• Uga Ulagalla (Ulagalla Resort) — Cultural Triangle / Anuradhapura area. Individual one‑bedroom pool villas (standalone, private plunge pools) set in a secluded manor‑estate — very popular with couples. (honeymoonguidesrilanka.com)
• Ceylon Tea Trails — Central Highlands (Hatton/Nuwara Eliya area). Restored planters’ bungalows that can be booked exclusively (private bungalow stays with butler service) — romantic highlands option for two. (brandradar.org)
• Kahanda Kanda — Galle region. Small boutique luxury hotel with individually designed suites/villas (including a honeymoon villa) and options with private terraces or private pools. (thetimes.co.uk)
• The Kandy House — Kandy (hill country). A villa‑style heritage manor offering private house/suite accommodations in gardens — well suited to couples seeking a private heritage villa experience. (brandradar.org)
• Saman Villas (Jetwing Saman Villas) — Bentota / West Coast. Boutique villa‑style layout; some standalone suites/villas include private plunge pools and are geared toward couples. (en.wikipedia.org)
• Aditya Resort — South Coast (Rathgama/Galle area). Small luxury property with private pool villas and one‑bedroom suites with plunge pools (aimed at honeymooners/couples). (aditya-resort.com)
• Diyabubula (Barberyn Art & Jungle Hideaway) — Dambulla / Cultural Triangle. A tiny luxury hideaway of a handful of villas — very private and intimate, suited to couples who want solitude and artful design. (en.wikipedia.org)
• Wild Coast Tented Lodge — Yala / South East coast. Luxury tented “cocoons” with private plunge pools in many units — intimate beachfront/jungle edge setting that appeals to couples. (vanityfair.com)

Quick notes and tips

• “Private villa” can mean different things: fully standalone villas with private pools (Uga Ulagalla, some Cape Weligama categories), private bungalows bookable exclusively (Ceylon Tea Trails), or secluded pavilion‑style suites with private terraces/plunge pools (Amanwella, Saman Villas, Aditya). If you need strictly standalone villas with private pools, prioritize Uga Ulagalla, Cape Weligama private‑pool villas, Aditya and some Saman Villas categories. (honeymoonguidesrilanka.com)
• Many properties have a small number of true one‑bedroom private villas (book early, especially in high season). Availability, exact villa layouts and whether a villa is single‑unit or part of a cluster vary by property — I can check specific villa categories and live availability for dates you’re considering if you’d like.

If you want, I can: (a) narrow this to a specific region (south coast, hill country, cultural triangle), (b) show typical price ranges or sample villa types, or (c check availability/rates for particular travel dates (I’ll look those up live).