The Ministry of Forests says the B.C. firefighters included 10 three-person, initial-attack crews and one representative of the Wildfire Management Branch.
Yukon's request for assistance was made through the Canadian Interagency Forest Fire Centre, which co-ordinates resources between provinces and territories.
The ministry says the jurisdiction that requests the assistance bears the costs, and enough resources remain in the province to fight B.C. fires.
B.C. has also loaned 21 personnel, four fixed-wing aircraft and a helicopter to Alaska, while 77 B.C. firefighters currently serving in Alberta are expected to return home Wednesday.
The ministry says crews can be deployed outside B.C. for as many as 19 days but can be called back at any time.