Evidently 4.1m of those sales were made during the period between 23rd November and 4th January.
Sony also noted that PlayStation Plus subscriptions surpassed 10.9m as of 2nd January.
On the software side, 81.8m PS4 games have been sold.
Sony will no doubt be delighted with sales of PS4, which went on sale in November 2013. It's the fastest-selling console ever in the UK, and has continued to outpace sales of the PlayStation 2, which ended up selling over 150m units.
Microsoft has yet to offer an updated sales figure for Xbox One, but in November 2014 Xbox corporate vice president of marketing, strategy and business, Yusuf Mehdi, said 10m units had been sold to retailers.