Including their brandname chains:
- Atlantic Cash & Carry
- Atlantic Superstore
- Axep
- Bloor Street Market
- Dominion
- Les Entrepôts Presto
- Extra Foods
- Fortinos
- Freshmart
- L’Intermarché
- Loblaws / Loblaw GreatFood / Loblaws CityMarket
- Lucky Dollar Foods
- Maxi / Maxi & Cie
- NG Cash & Carry
- No Frills
- Provigo
- Real Canadian Superstore
- Shop Easy Foods
- Shoppers Drug Mart / Pharmaprix
- SuperValu
- T & T Supermarket
- Valu-mart
- Wholesale Club / Club Entrepôt
- Your Independent Grocer / Independent CityMarket
- Zehrs Markets
Yes there are other big oligopoly chains like metro, Sobeys/Safeway, Pattison, but I think it’s best to start with one major chain to see how much coordinated action can affect them.
There’s a lot of options, including big and small chains and local independents depending on your needs. It may be worth boycotting other chains in some order to keep everyone on their toes, but none have been as blatantly greedy as Loblaws for sure.