According to The Sun, Mr Johnson arrived in Glasgow earlier on Thursday.
Police Scotland have confirmed they've already received “a small number of complaints' regarding the Prime Minister’s visit to Scotland.
A spokesperson for Police Scotland said: “We have received a small number of complaints regarding Prime Minister Boris Johnson's visit to Scotland.
“This is a working visit in his official capacity as Prime Minister and we are policing the event appropriately”.
It is thought Mr Johnson will use his visit to argue the Union has been integral in tackling the pandemic – administering the Covid-19 vaccine, providing coronavirus testing and giving economic support.
Speaking ahead of his trip north, he said: “The great benefits of co-operation across the whole of the UK have never been clearer than since the beginning of this pandemic.
“We have pulled together to defeat the virus, providing £8.6 billion to the Scottish Government to support public services whilst also protecting the jobs of more than 930,000 citizens in Scotland.
“We have a vaccine programme developed in labs in Oxford being administered across the United Kingdom by our Armed Forces, who are helping to establish 80 new vaccine centres across Scotland.
“That’s how we are delivering for the people of Scotland so we can ensure the strongest possible recovery from the virus.”
The Prime Minister's visit comes days after the SNP unveiled its roadmap to independence.
The party has said that should there be a pro-independence majority elected in May’s Holyrood election, it will announce plans to hold another referendum even if Westminster again denies permission, and dare the UK Government to challenge it in court.
The SNP has said Mr Johnson’s trip to Scotland today is evidence of a “prime minister in panic”, after 20 consecutive polls have shown a majority support for independence.
Keith Brown, the SNP’s Depute Leader, has accused the Prime Minister of mimicking Donald Trump’s attempts to block democracy.
Keith Brown MSP said: “Clearly, Boris Johnson is rattled. By branding this campaign trip as ‘essential’, this is clearly a Prime Minister in panic, who knows the Tories are losing the argument on independence.
“Twenty polls in a row have shown that a majority of voters believe Scotland’s future should be in Scotland’s hands – not Boris Johnson’s.
“Scotland didn’t vote for this Tory government, we didn’t vote for Brexit and we certainly didn’t vote for Boris Johnson.
“Yet, in the middle of a global pandemic, we’ve been ripped out of the world’s biggest single market against our will causing havoc for businesses and piling even more pressure on our NHS. No wonder that more and more people in Scotland want the right to choose their own future.
“The longer Boris Johnson reads from the Trump playbook of democracy denial, the more support for Scottish independence will grow.”
SNP Commons spokesman Tommy Sheppard said that Mr Johnson is “more than capable of patronising us from his office in Whitehall”.
He told MPs on Thursday: “I would like to ask for a debate on the role of Government ministers and the Prime Minister in particular in setting an example by following the rules which they make for others during the lockdown.
“I know of course that every time the Prime Minister opens his mouth on the subject, his ill-informed views drive support for Scottish independence upwards and I know also that his stage-managed visits to selected Scottish supporters make the SNP’s case for it.
“So in normal circumstances, he would be most welcome, but these are not normal circumstances. We are telling millions of people not to leave their homes and only to make essential journeys.
“The Prime Minister is more than capable of patronising us from his office in Whitehall. So what exactly is so essential about his thousand mile-round trip to Livingston today?
“This gallivanting is a blatant piece of electioneering while most are focused on fighting Covid. But the real tragedy is that his actions will undermine the public health message which we all need to succeed.”
Speaking at Wednesday's daily coronavirus briefing, First Minister Nicola Sturgeon also questioned the need for Mr Johnson’s visit, insisting is is not “essential” at a time when political leaders are urging people to stay at home – although she stressed the Prime Minister is welcome in Scotland.