Mr Ellis was defending a very narrow majority of just 807 votes following the 2017 vote, but managed to see off the challenge of Labour candidate Sally Keeble by securing 21,031 votes.
That latest ballot means the former barrister, who had been serving as Solicitor General prior to the election being called, has increased his majority comfortably to 5,487.
Acknowledging his victory, he said: "I want to thank my staff and volunteers. I am privileged to serve as an MP for the town where I live and I was brought up. I will continue to serve to the best of my ability."
Ms Keeble has contested the seat for every one of the seven elections that have taken place since 1997. She had won the first three to serve as the MP from 1997 until 2010. But it is the fourth time that she has lost out to Mr Ellis ever since the turn of the decade.
Ms Keeble scored 15,544, which was fewer than the 18,258 she scored two years ago.
On hearing the results, she told Mr Ellis on stage: "The people of Northampton North have put a very great trust in you. I hope you will look after them. I hope you assist our homeless who need a roof over their heads. I hope you make sure that nobody relies on food banks."
The Liberal Democrats came in third place, with Martin Sawyer scoring 2,031 votes, while Green Party candidate Katherine Pate completed the pack with 953 votes.
It rounded off what appears to have been a successful night for the Conservatives, with a healthy majority on the cards, and a disappointing night for Labour, with leader Jeremy Corbyn announcing he would be stepping down.
General Election 2019: LIVE from Northampton Tory Michael Ellis pledges to serve Northampton North 'to best of my ability' as Labour's Sally Keeble urges him to support the homelessConservative candidate thanks people of Northampton South 'for placing trust and confidence in me'Labour's Gareth Eales says he is 'sorry' for what election result means for 'people of Northampton South'Gallery of pictures from the Northampton countsTurnout slightly down for Northampton North and SouthGreen Party candidate in Northampton South calls for electoral reformNorthampton Lib Dem candidates say exit poll results are a 'disaster'Northampton Conservatives thrilled with exit poll results as they say Brexit message was 'hammered home'Labour confident they'll take both Northampton seats despite crushing exit poll forecastsChris Heaton-Harris returns as Daventry MP