By Bus from Victoria, Nanaimo, or Vancouver

ferry-to-cortes

Islandlink Bus provides scheduled bus service from downtown Victoria or Nanaimo ferry terminal to Campbell River, 250-954-8257 or 604-970-4990.
Ambassador Shuttle provides scheduled shuttle service from Comox to Campbell River, 877-339-5252.
Greyhound runs scheduled bus services linking Victoria and Nanaimo to Campbell River.

After you arrive in Campbell River, you can catch Cortes Connection (make phone reservation), get on the ferry and hitchhike over Quadra, or book Quadra Taxi to get from Quathiaski Cove terminal to Herriot Bay terminal, and in Herriot Bay ferry terminal get onto Cortes ferry.

The Cortes Connection offers a shuttle service from downtown Campbell River to Cortes Island, 250-935-6911.
The Quadra Taxi can take you from one Quadra ferry terminal to the other, 250-205-0505.

There is no direct bus from Vancouver to Campbell River. Instead, you can take a bus (or taxi) from Vancouver to the ferry terminal in Horseshoe Bay, continue on the ferry as foot passenger, then take Islandlink (you need to pre-book it) from Nanaimo to Campbell River.