My take: Event calendars for Trondheim are usually outdated by the time they rank on Google. I rebuild this list each quarter from the official venue and tourism-board sites, then cross-check dates with the local press. If you see something here, it's confirmed for 2026.
3 Events Worth Planning Around
🎭 Olavsfest
Late July — Medieval and liturgical music around the cathedral.
🎭 Trondheim Jazz Festival
May — International jazz across waterfront venues.
🎭 Pstereo
August — Two-day indie rock festival on Marinen.
How to Buy Tickets
For major cultural events (opera, classical, theatre), buy direct from the venue's site — you'll get better seats and avoid resale markups. For tours, museums and skip-the-line attractions, we use GetYourGuide and Tiqets because they mobile-deliver the ticket and let you cancel up to 24h before.