The deal marks the return of the brand to TV for the first time in 15 years.
It starts with the first episode of the new series on Saturday and includes a one-off special, when Piers Met Lord Sugar.
Five-, 10- and 15-second break bumpers will appear during the programme.
James Stocker, marketing controller for dark spirits at First Drinks, said: “As a major player in the whisky category, we really wanted to invest heavily in Grant’s this year.
“The ITV deal with will demonstrate our commitment to Grant’s whisky and will really end the year on a high for the brand.
“The sponsorship will enable us to reach a massive audience, including a very high proportion of Grant’s core target consumers and the Life Stories theme fits perfectly with the brands own rich heritage and story of its success to date.”
There will be online ads to publicise the sponsorship and shelf-barkers in the take-home trade.