This includes those over 50, unpaid carers, and those with underlying health conditions.
Prime Minister Boris Johnson called the milestone “hugely significant” and said more than 32 million people in the UK had been given a jag.
It comes as some 83 per cent of Scots in the 50 to 55 age group have been given a vaccine, along with 86 per cent of those aged 16 to 64 with an underlying health condition.
First Minister Nicola Sturgeon, 50, is due to receive a vaccine on Thursday.
The Scottish Government has not yet commented on the announcement.
Prime Minister Boris Johnson said: "We have now passed another hugely significant milestone in our vaccine programme by offering jabs to everyone in the nine highest risk groups.
“That means more than 32 million people have been given the precious protection vaccines provide against Covid-19.
“I want to thank everyone involved in the vaccine rollout which has already saved many thousands of lives.
“We will now move forward with completing essential second doses and making progress towards our target of offering all adults a vaccine by the end of July.”
UK Health and social care Secretary Matt Hancock said: ‘I’m delighted the team have done such an amazing job to hit yet another target early.
‘The tide of this pandemic is turning in every part of the UK, as every day more and more people are being given the safety of a Covid-19 vaccine.’
Latest figures show 2,668,723 people have been given a first dose in Scotland, just under 61 per cent of the adult population. In England, that figure is 62 per cent.
Scotland is now set to move to Phase 2 of the vaccine rollout, with all those over 18 to receive a first dose by the end of July.
Some 36 per cent of those aged 40 to 49 in Scotland have been given a first dose, along with 25 per cent of those 30 to 39 and 16 per cent of under 30s.
The JCVI is expected to soon publish guidance on how the next cohorts will be vaccinated.