McGeoghan's appointment follows Trinity Mirror yesterday completing the purchase of MEN Media as part of the deal which saw it take control of the 32 regional newspapers previously owned by Guardian Media Group.
Georgina Harvey, managing director of Trinity Mirror Regionals, addressed MEN staff this morning.
She said: "This iconic newspaper has a rich and important heritage and Maria's passion and experience will guide the title - across all platforms - to further and future success."
McGeoghan, 48, joined the MEN as assistant editor in 1998. She was appointed deputy editor in 2006 and became acting editor in October last year. Before joining the MEN, she held a number of senior editorial jobs at the Liverpool Echo.
She said: "This is a great paper with a fantastic team of people who work very hard to set the news agenda in Greater Manchester.
"I'm also very proud of our weekly titles which continue to serve their communities so well.
"This is a very exciting time for our newspapers and I'm looking forward to being part of the team driving for a successful future."