The screen will be installed at the centre until August 20, allowing shoppers to take a break and watch some of the major sporting events in the calendar, including Wimbledon.
Film-goers will be catered for with movie classics showing on the giant screen every Friday, Saturday and Sunday from July 21.
Centre director Kevin Duffy said: “ ‘Screens Court’ will give our guests the opportunity to watch live sport in the outdoors.”
centre:mk has put the finishing touches to its new Guest Service Lounge, part of the £60 million investment programme in the shopping centre and which opened in June.
The lounge includes baby-changing facilities, toilets and areas for shoppers to take a break.
Mr Duffy said: “As Milton Keynes enters its 50th year, we wanted to reward our customers with contemporary facilities in which they can feel like true VIPs. This exciting new makeover will secure centre:mk as a modern hub and an exciting place to draw in visitors from across the UK.”