The SKU will be available exclusively in the cash and carry sector with price-marked £8.99 bottles.
The launch follows trials carried out earlier in the year.
Senior brand manager Amy Mooney said: “The trial was extremely successful, so it made sense to roll it out nationally within convenience.
“Shoppers really embraced this new format. During the trial, the 50cl variant helped to grow a store’s total vodka category sales by an average of 2.3% and Smirnoff’s sales by an average of 4.4%.
“Retailers have a great opportunity to build their spirits sales by stocking the 50cl size and attracting customers who are likely to be looking for other items for their night in.”?Diageo said vodka accounted for 37% of non-70cl bottle sizes of spirits in the UK.
Diageo has also unveiled a new bottle design for Black Bush Irish whiskey.