Here are well-known hotels in Colombo that offer meeting rooms, conference halls and event services — with a brief note on typical capacities so you can match size to your event. I’ve listed a mix of large-ballroom venues and hotels with smaller boardrooms.

Large conference / ballroom venues

• Hilton Colombo (World Trade Centre) — multiple meeting rooms and a large pillar‑free Grand Ballroom; capacities up to several hundred and large total event space. (Hilton.com)
• Taj Samudra Colombo — several halls/ballrooms (e.g., Samudra Ballroom, Grand Crystal Ballroom) and lawns; ballrooms for 200–500+ and outdoor lawns up to ~2,000. (tajhotels.com)
• Cinnamon Grand Colombo / Cinnamon Hotels — multiple meeting rooms, ballrooms (Oak Room, Ivy, Aspen, etc.) for a range from small meetings to large conferences. Also Cinnamon Lakeside has large ballrooms and suite boardrooms. (cinnamonhotels.com)
• Shangri‑La Colombo — meeting & events facilities plus co‑working and private meeting rooms (Co-nnect); suitable for small to large corporate events. (Shangri-La.com)

Medium / flexible venues (boardrooms, mid‑size halls)

• Galle Face Hotel — several meeting rooms and a Grand Ballroom; rooms for small board meetings up to ~200 (multiple smaller function rooms of 15–90 pax). Good for seaside/heritage setting. (gallefacehotel.com)
• The Kingsbury Colombo — range of meeting rooms, private boardrooms and mid‑size function rooms (boardroom-style rooms for ~10–20 and larger rooms for bigger meetings). (thekingsburyhotel.com)

Other hotels to consider (depending on location, budget and capacity)

• Cinnamon Lakeside Colombo — large ballrooms, multiple conference rooms, boardrooms and outdoor waterside venues. (cinnamonhotels.com)
• Hilton Colombo Residences — grand ballroom and flexible meeting spaces if you prefer that property’s offerings. (Hilton.com)

Quick planning tips

• Decide expected attendance range first (e.g., 10–30, 30–100, 100–300, 300+) and pick hotels whose listed capacities match. (The listings above include examples of room capacities from each hotel.) (cvent.com)
• Ask each hotel for a current “delegate package” (half/day/full‑day) which usually includes room hire, AV, coffee breaks and basic A/V — compare total cost per person. (gallefacehotel.com)
• Confirm AV specs, breakout rooms, Wi‑Fi bandwidth, floor plans and whether rooms are pillar‑free if you need staging/exhibits. (cvent.com)

If you want, I can:

• Narrow this to a specific area of Colombo (Galle Face Green, Fort, Cinnamon Gardens, near the airport), or
• Compare 3–5 hotels side‑by‑side with explicit capacities, sample pricing ranges (if you give event date and guest count), and contact/email for proposals.

Which would you like me to do next?