The Wayback Times and Canadian Stamp News are good resources for Canadian events that might have postcard vendors. For USA shows check the Postcard History Magazine calendar.
Quebec City Old Paper Show
Sat. & Sun. October 26/27th, 2024 from 10am
Full details here.
Old Book and Paper Show
Sun. November 10th, 2024
Japanese Canadian Cultural Centre, 6 Sakura Way
Admission $12.00. TTC accessible, free parking.
Info from: Antique Shows Canada
2025 Annual TPC Show
Sun. February 23rd, 2025, 10am-5pm
Japanese Canadian Cultural Centre
6 Sakura Way, Toronto, M3C 1Z5 (JCCC web-site)
Info from: Victor Caratun Email
30th Annual Quebec Postcard Club Show
TBC June 2025 Montréal
Info from: Facebook: Club des cartophiles quebec
or Simon Beauregard Email
Eastern Ontario Postcard, Postal History & Ephemera Show
September TBC 2025 9am-3pm
Wall Street United Church, 5 Wall St.
Brockville, ON (map) free admission & parking
Golden Horseshoe Postcard Club Show & Sale
Sept. TBC 2025 10am-4pm
Ukrainian Catholic Church, 821 Upper Wentworth
Hamilton, ON L8V 2H7 (map) free admission & parking
Info from: Carl Schlosser Email
International Show Calendars
USA Shows from Postcard History Magazine
U.K. Shows from Postcard Traders Association