The website has achieved this milestone figure just four months after it launched with the aim to appeal to a different audience to Trinity Mirror's existing sites.
UsVsTh3m features original, curated and interactive content which is easy to use and share on mobile phones and tablets, says Trinity Mirror.
Of the one million unique users to visit in September so far, 49% accessed the site from mobiles or tablets and 51% from desktops. 64% of them were from the UK.
‘Down with the kids’, which features “12 questions that rate whether you’re up to date”, is the most popular interactive post on the site with 470,000 people playing it.
300,000 users have played the ‘You can’t do simple maths under pressure test’, the second most popular interactive story on the site.
And, 266,000 users have tried to guess where Damascus is.
Malcolm Coles, Digital Product Director at Trinity Mirror said: “UsVsTh3m only launched at the end of May. It's an amazing achievement by the team to have grown so quickly and shows the importance of experimentation for publishers.
UsVsTh3m’s Twitter feed has also grown significantly, gaining nearly 10,000 followers in the four months since launch.
