The ads from the Forever London campaign highlighting Beefeater's London roots, will appear on the cabs until November.
Tip up seats inside the branded cabs will also display information on Beefeater's production process and drivers will hand out cocktail recipes printed on Beefeater-branded receipts to passengers.
Last year Pernod Ricard gave Beefeater's branding an overhaul and launched the Forever London campaign, which uses cultural London icons to promote the spirit's links with the capital.
Nick Blacknell, brand director for Beefeater said: “Black cabs are such a recognised London icon that it is logical for Beefeater to showcase its advertising in this creative manner, offering a visual representation of Beefeater’s traditional heritage and its place in contemporary London.
"In addition, the much-loved black cab features in three of the advertising executions launched earlier this year to great critical acclaim.”