The watchdog's International Communications Market Report showed that the average British mobile account burned through 424MB of data in December 2011, moving the nation ahead of Japan on 392MB.
Ofcom's report also confirmed that the average British shopper spends more than £1,000 a year purchasing goods online, placing them ahead of Australia on £842 and Sweden on £747.
Average phone bills, line rental and mobile broadband costs were found to be less expensive in the UK than France, Germany, Italy, Spain and the US, but Ofcom noted that the gap is gradually narrowing.
British users led the global rankings for the adoption of smart TV and digital video recorder hardware and are the most likely to watch television online. Almost a quarter of Britons frequently use on-demand services such as BBC iPlayer and 4OD.
"What's clear from this report is that Britain is a nation of early adopters and telly addicts. We're not only the most data-hungry in the world when it comes to using mobile internet on our smartphones, but we're also global leaders in embracing new TV technology too," said Ernest Doku, telecoms expert at uSwitch.com.
The average UK viewer watches 242 minutes of television each day, with only Italy (253 minutes) and the US (293 minutes) watching more.
"Britain's TV culture has undoubtedly been fuelled by the economic climate. The cost of living has soared and we now have less to spend on social activities like going to the cinema and out to dinner. Plus, there's the lure of primetime shows like X Factor and Strictly to keep us on our sofas on a Saturday night.
"This, coupled with prices for TV packages becoming ultra competitive - they now start at £9 per month - has helped cement our status as nation of square-eyed consumers."
Doku went on to say that his company's research suggests that Britons spend £600 a year on TV subscriptions alone, and a further £934 on gadgets, apps and other downloads.
He added: "In spite of the fact we're all trying to budget, many Brits are fully prepared to spend a lot more than that on TV. According to uSwitch.com research, 17% spent more than £50 per month on TV subscriptions alone - that's a whopping £600 a year. In fact, Brits spent more on TV than they did on their mobile phones.
"But tech-loving Brits didn't stop there. Last year consumers spent a hefty proportion of their hard earned cash – £934 each, or £42billion collectively - on gadgets, apps and downloads in 2012."