WBZ-TV first signed on the air on June 9, 1948, as the only television station that was built and signed on by the Westinghouse Broadcasting Company, and as a primary NBC affiliate on VHF channel 4, which its radio station of the same name was also long associated with the Red Network.
The logo design, especially the font (called "Westinghouse" or "Anklepants" (due to a similar typeface) by some people), was originally introduced when then-owner Westinghouse Broadcasting (Group W) introduced its design language in 1963.
In 2018, this iconic "4" was revived to celebrate its 70th anniversary.
The "4" became italicized in 1987. Then-sister station KDKA-TV in Pittsburgh would later follow suit in 1991.
On January 2, 1995, in a group deal with then-owner Westinghouse, WBZ-TV switched affiliations with then-CBS affiliate WHDH-TV (VHF channel 7). WBZ would also debut a new tagline called The Tradition Continues when it switched to CBS that year. Westinghouse would later acquire CBS, making WBZ-TV a O&O.
The "CBS 4" name was abandoned in 2007 in favor of it's call letters. It similar to ITV1 logo used 3 years earlier, but the color scheme slightly darker and the font is different. Their call letters and CBS logo are white
On December 12, 2011, WBZ adopted a new look and a new news set, at the same time switching to an amber-blue color scheme. This logo is formed from the combination of the "CBS 4" logo used from 2004–07 and the "WBZ" logo used from 2007-11.