The gargantuan download marathon was noted in analysis by mobile research firm Flurry.
Flurry estimated that in the seven days after 25 December more than 20 million iOS and Android devices were activated, and 1.2 billion apps were downloaded.
The record-breaking haul was completed in the week when more mobile devices were activated than at any other time of the year – most thanks to gifts given over the holidays.
An estimated 6.8 million iOS and Android devices were activated on Christmas Day alone, and 242 million apps were downloaded by excited Christmas gift recipients.
The United States was responsible for 509m of those downloads (42.3%) and China came second, with about around 100m. The UK was third on the list, notching up around 81m apps downloaded.
Flurry noted that downloads were lower in non-religious countries – 60% of Chinese people consider themselves atheist or agnostic – where Christmas was not as significant a factor.
The research firm says that it completed its analysis by including its analytics service in 20% of all apps downloaded from the App Store and Android Market.