Announced last month, the new phone is a compact version of Samsung's flagship Galaxy S3. It features a 4-inch AMOLED screen, compared with the 4.8-inch display in its bigger brother.
Available in blue or white, the Mini will come with Android 4.1 Jelly Bean, although not the latest 4.2 version that was announced earlier this week.
Samsung has added a range of additional content to the operating system, such as Chat On, Buddy Photo Share, Social Tag and the 'Official Top 40 Charts' app.
The Mini will also launch with a range of free content, including games The Sims 3 and Bejewelled 2, plus users get 50GB of free Dropbox storage for two years.
"Our latest addition to the Galaxy portfolio, the Galaxy S3 Mini brings the high performance, intuitive ease-of-use and nature-inspired design of the Galaxy S3 in a new elegant yet compact form," said Samsung's Simon Stanford.
"Following the massive success and popularity of the Galaxy S3 and all its features, we are confident customers will enjoy the Galaxy S3 Mini."
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The Galaxy S3 Mini will be available to buy in the UK across all major mobile networks from high street and online retailers on November 8.
Samsung has not yet confirmed the exact pricing, but retailer Handtec is offering the phone SIM-free for £293.99.
Phones 4u also says on its pre-order page for the Mini that it will be free on plans of £25-a-month or higher.