The region has become the first to hit the milestone after the booster programme – the third jab – was kick-started on September 16 last year.
It comes as Covid cases have started to rise with 35,930 currently in the West Midlands in the past seven days, a rate of 602.7 per 100,000.
Roz Lindridge, the NHS England and NHS Improvement director responsible for overseeing the vaccination programme across the Midlands, said: "The NHS vaccination programme in the Midlands has saved countless lives, reduced pressure on the NHS, and built a wall of defence against the serious effects of Covid.
"It is fantastic to see such strong uptake for the booster vaccine, with over six million people coming forward to book their extra dose.
"Spring boosters have also got off to a superb start. Getting your spring booster will help increase your protection from the rising Covid transmission rates and cut your risk of becoming seriously ill with COVID and being admitted to hospital. I would urge anyone invited for a spring jab to come forward as soon as possible.
"NHS staff continue to work hard across the Midlands to deliver the Covid vaccine to all eligible groups with five to 11s the latest to start receiving theirs. The vaccination programme continues to be vital in helping to protect against potential future waves of Covid."
Roughly 85 per cent of people in the West Midlands aged between 55 and 59 have received their third jab. And people who have missed out on getting theirs should book an appointment through the NHS, with the offer being "evergreen".