Boris Johnson – $4 million

After Theresa May stepped down in 2019, Queen Elizabeth II appointed Boris Johnson as the Prime Minister. That made him the second person born outside the British Isles to serve as Prime Minister. His re-election later the same year helped his conservative party attain its largest majority in three decades. 

Previously, Johnson held the office of the Mayor of London between 2008 to 2016. Parliament ordered him to apologize for a Ministerial Code breach when he failed to declare £50K (estimated $70.5K) earnings. The amount came from his 12-month contract with the Telegraph Media Group.