The Island is home to a ton of great annual and totally random one off festivals and events.  This list is by no means exhaustive but it gives you a place to start and an idea as to what is within reach here from cultural and historical events to world class sporting events, food and wine festivals and the list rolls on……
Festival of Trees Nov 2018 – Jan 2019
Habitat for Humanity 9th Annual Gingerbread Showcase Nov 18-Jan 2019
Wildlife Photographer of the Year Exhibition at Royal BC Museum Dec -Apr 2019
Victoria Film Festival   Feb 2019
Song & Surf Music Festival Feb 2019
Capital City Comic Con Mar 2019
Greater Victoria Performing Arts Festival    Apr -May 2019
Uno Festival -Contemporary solo theatre and performance   May 2019
Victoria Highland Games and Celtic Festival    May 2019
Swiftsure International Yacht Race    May 2019
TD Victoria International Jazz Festival    June -July 2019
Victoria Ska Fest    June 2019
Victoria Pride    July 2019
Phillips Backyard Weekender Music festival   July 2019
Vancouver Island Music Festival (Comox Valley)   July 2019
Rock the Shores Music Festival   July 2019

Free B Film Festival Aug 2018
Symphony Splash Aug 5, 2018

Victoria Dragon Boat Festival    Aug 10-12, 2018
Victoria Fringe Theatre Festival    Aug 22-Sept 2, 2018
Victoria Buskers Festival Aug 31-Sept 3, 2018
Vancouver Island Blues Bash Sept 1-3, 2018
Victoria International Cycling Festival
Victoria Classic Boat Festival    Sept  2018
Rifflandia Music Festival    Sept 13-16, 2018
Goodlife Fitness Victoria Marathon    Oct 7, 2018
Art of the Cocktail    Oct 13-14, 2018

Other great local resources for event listings include:
Tourism Victoria Calendar of Events
                                                                 Downtown Victoria Business Association (DVBA) Calendar of Events
                                                                                                           Tourism Vancouver Island Festivals and Events
                                  Chatterblock Victoria – especially great for families with young kids