|City of license||Toronto, Ontario|
|Broadcast area||Greater Toronto Area, Central Ontario|
|Branding||CBC Radio One|
|Frequency||99.1 MHz (FM)|
|First air date||1925|
|Callsign meaning||Canadian Broadcasting Corporation, Great LAkes|
|Former callsigns||CKGW (1925-1932)
|Former frequencies||910 kHz (AM) (1925-1941)
740 kHz (AM) (1941-1999)
|Owner||Canadian Broadcasting Corporation|
|Sister stations||CBL-FM, CJBC-FM, CJBC, CBLFT, CBLT|
|Website||CBC Radio One|
The station originally aired in 1925 as AM 910 CKGW, a commercial station owned by Gooderham and Worts. Due to the instability of frequency allocations in North America at the time, the station's frequency changed several times over the next number of years, to 960, 690, and finally clear channel 840. In 1932, the station was leased by the CBC's predecessor, the Canadian Radio Broadcasting Commission. It used the call letters CRCT until 1937, when the station was purchased outright by the CBC and adopted the callsign CBL, moving to a new transmitter facility in rural Hornby. With NARBA in 1941, the station moved to 740 kHz; its former channel, now 860, went to CFRB. (See Canadian allocations changes under NARBA.)
Between 1938 and 1943, CBL had a rebroadcaster, CBY, to supplement coverage in Toronto. CBY broadcast on 960, switching to 1420 in 1939 and then to 1010 in 1941. CBY is now CJBC 860, Toronto's Première Chaîne station.
In 1946, CBL-FM was launched, bringing the CBC's FM network (now known as CBC Radio 2) to Toronto. It originally broadcast on the same 99.1 frequency now used by CBLA, but moved to 94.1 in 1966. (The 99.1 frequency was vacant until 1977, when it was assigned to the CKO radio network. CKO ceased operations in 1989, and the frequency was again vacant until it was assigned to CBLA.)
The CBC's transmitter tower on Jarvis Street in downtown Toronto, built in 1952, was for many years the tallest structure in Canada. The facility was used by CBL (studios only), CBL-FM, CBLT, CBLFT, CJRT and TVOntario. In 1976, almost all broadcast signals in Toronto moved to the CN Tower. Although the Jarvis St. transmitter was no longer in use, the CBC continued to use the studio facilities at that site until moving to the Canadian Broadcasting Centre in 1992.
CBL established a large low-power relay transmitter (LPRT) network in Northern and Central Ontario during the 1950s and 60s. These transmitters, all on AM frequencies, mainly rebroadcast the CBL signal but also offered some separate regional programming directed towards the regions served by the LPRT network in place of some local Toronto programming. One example of this was the daily Northern Ontario Report, which aired in the late afternoon. Most of these LPRT network transmitters now rebroadcast CBCS in Sudbury or CBQT in Thunder Bay. Some of these transmitters have switched to FM as well, or have been shut down as FM transmitters covering areas served by multiple AM transmitters have signed on.
In 1997, CBL applied to the Canadian Radio-television and Telecommunications Commission for conversion to FM. AM 740's daytime signal easily covered Buffalo, New York; Erie, Pennsylvania and Youngstown, Ohio. It was also powerful enough to serve as the CBC outlet for the Waterloo Region as well. Its nighttime signal reached much of the eastern half of North America (including three-fourths of Canada). Howeveer, radio frequency interference made the station nearly unlistenable in some parts of downtown Toronto. In a controversial decision, the CBC was awarded the 99.1 frequency over Milestone Radio, who had applied to open an urban music station, which would have been the first station operating under that format in Canada, to serve the city's large black community. Adding to the controversy of the CBC being awarded a station on the FM band in the country's biggest market, 99.1 was believed at the time to be the last available FM frequency in the city.
On June 18, 1999, the station completed its move to FM, adopting the CBLA calls. CBL remained in operation for an additional day, broadcasting a recorded loop listing alternative FM frequencies for any remaining listeners. The final announcement ran thus:
This is CBC Radio One, broadcasting from the Hornby transmitter at 740 AM. In the Toronto area, we will now move to 99.1 FM, with additional frequencies throughout southern Ontario. This transmitter has served the community well since 1937, and has been at 740 AM since 1941. This is the end of an era in Canadian broadcasting history. Now, signing off, from CBL, adieu.—Philip Savage, CBC Communications department
The CBC subsequently surrendered two relay transmitters outside the city which overlapped with the CBLA signal. In 2000, the CRTC awarded one of the new frequencies to Milestone, who launched CFXJ in 2001, and the other to Aboriginal Voices, who launched CFIE in 2002. The Hornby transmitter was leased to the new occupant of 740, CHWO, in 2001. That station is now known as full service oldies station CFZM.
The Jarvis Street transmitter site was demolished in 2002 to make way for the RadioCity condominium development.
Local programming 
The station's local morning program is Metro Morning, and Toronto's most popular radio show in the ratings since 2004. Now hosted by Matt Galloway, the program was previously hosted by Andy Barrie from 1995 to 2010. Here and Now, (currently without a permanent host), airs in the afternoon slot. On weekend mornings the station produces Fresh Air, hosted by Mary Ito and heard throughout Ontario except in the Ottawa region. Saturday afternoons the station broadcasts an arts and culture magazine, Big City, Small World, hosted by Garvia Bailey.
The station also produces a second morning program, Ontario Morning, which airs on most of the network's transmitters in Southern Ontario outside of the Toronto, Kitchener-Waterloo, Ottawa and Windsor metropolitan areas. Ontario Morning is currently hosted by Wei Chen. Similarly, the aforementioned Big City, Small World is replaced by CBO-FM/Ottawa's Bandwidth on all of the station's rebroadcasters outside Toronto and Kitchener-Waterloo.
Since October 2005, Here and Now has begun at 3 p.m. on CBLA's main transmitter in Toronto, unlike most CBC Radio One stations whose local afternoon programs begin at 4 p.m. However, the station's rebroadcast transmitters outside of Toronto air regular CBC network programming for the first hour and join Here and Now in progress at 4.
CBLA's rebroadcaster in Crystal Beach, which serve areas within commuting distance of Toronto, normally air Metro Morning instead of Ontario Morning, but otherwise abides by the schedule used by other rebroadcasters – it carries neither the 3 p.m. hour of Here and Now, nor any other specially-scheduled programming specific to the Toronto area. (For example, special weekend editions of Metro Morning aired on CBLA during the 2010 G-20 Toronto summit; however, the Crystal Beach and Paris, Ontario transmitters carried a morning show originating from Ottawa, as did CBLA's other rebroadcasters outside Toronto.)
In September 2011, the CBC announced plans to launch a new local radio service for the Kitchener-Waterloo area beginning in fall 2012, re-using the existing transmitter, CBLA-FM-2 89.1 FM in Paris. On November 7, 2012, the CBC applied to the CRTC to convert CBLA-FM-2 to a self-sustaining FM radio station, which would carry national CBC Radio One programs, along with a minimum of 12 hours and 30 minutes a week of local programming.  The new station commenced programming on March 11, 2013, but was later forced to resume rebroadcaster-only service in April, due to a misunderstanding of the application details and the conditions of the repeater license.  The new station received full approval from the CRTC on April 25, 2013.  Prior to its sign-on, CBLA-FM-2 carried the same schedule as the provincial CBLA feed, apart from Metro Morning (Kitchener-Waterloo, like Crystal Beach, is also within commuting distance of Toronto).
CBLA-FM has the following rebroadcasters.
|City of license||Identifier||Frequency||Power||Class||RECNet||CRTC Decision|
|Bancroft||CBLV||600 AM||40 watts||LP||Query|
|Crystal Beach||CBLA-FM-1||90.5||319 watts||A||Query||98-428|
|Owen Sound||CBCB-FM||98.7||100,000 watts||C1||Query|
|Parry Sound||CBLR-FM||89.9||180 watts||A1||Query||92-783|
Former callsigns 
- Meaning of call letters
- Decision CRTC 97-362
- Fybush, Scott (1999-06-19). "CBL, Adieu" (MP3 audio news story). Retrieved 2008-05-18.
- Renhart, Anthony, "Andy Barrie battles Parkinson's; Popular CBC radio host comes out ‘as a guy with a disability'", Globe and Mail, June 29, 2007
- Canadian Broadcasting Corporation (2011-09-26). "CBC to introduce new local service to Kitchener-Waterloo". Retrieved 2011-09-26.
- Rubinoff, Joel (2011-09-27). "CBC to expand radio and internet presence in Kitchener and Waterloo by fall 2012". Waterloo Region Record. Retrieved 2011-09-28.
- Broadcasting Notice of Consultation CRTC 2012-616, CRTC, November 7, 2012
- "CBC launches new Waterloo Region station March 11". CBC News, January 22, 2013.
- "CBC temporarily takes KW morning show off air". CBC News. 2013-04-23. Retrieved 2013-04-23.
- Broadcasting Decision CRTC 2013-203, English-language FM radio station in Paris and licence amendment for CBLA-FM Toronto, CRTC, April 25, 2013
- CBC Toronto
- CBLA Toronto Radio History at Canadian Communications Foundation
- Query the REC's Canadian station database for CBLA-FM