Sparkling wines including prosecco and champagne led the way with sales up by 36%, said market research firm Kantar Worldpanel.
Kantar credited "promotional events across a number of retailers which successfully tapped the nation's celebratory mood".
The uplift came despite an otherwise flat UK grocery market.
Fraser McKevitt, head of retail and consumer insight at Kantar Worldpanel, said: "While overall [grocery] sales growth has been slow, consumers have been keen to celebrate Britain's Olympic and Paralympic golden summer, boosting alcohol sales."
He said that Tesco's summer Drinks Festival had helped to grow its alcohol sales "faster than any other major category" at the store, while Waitrose and Co-op also booked strong drink sales.
In the 12 weeks to 11 September, overall UK grocery sales increased by 0.3% from a year earlier to Â£24.7bn, said Kantar Worldpanel.
This was while grocery inflation was negative, at -1.1%, meaning shoppers were paying less for food and drink than they were in 2015.
Tesco remained the UK's largest operator with a 28.1% share of the grocery market, although its sales have not yet returned to growth.
Its 0.2% year-on-year decline, however, was its "best performance" since March 2014, said Kantar Worldpanel.
Sales at its closest rival Sainsbury's fell by 1.4%, reflecting a lower price strategy and leaving the retailer with a 15.9% share of the market.
Asda's sales were down 5.4%, leaving it with a 15.7% stake, and Morrisons' fell 2.3%, leaving it with 10.4%.
The fastest risers were discount operators Aldi, whose sales increased by 11.6%, and Lidl where they grew 9.5%.
Mr McKevitt said: "The discounters are helping drive the industry-wide growth in premium own-label lines, with marketing campaigns moving away from showcasing only price to a focus on quality.
"Shoppers now spend an average of Â£19.24 when visiting the discount retailers and at a time of falling prices this increase of 4% is not to be sniffed at."
Alcohol sales jumped 8.5% in the summer as shoppers celebrated the UK's success at the Olympics, a study suggests.