A dyed-in-the-wool Arsenal fan, the British journalist is known for strong criticism of Arsene Wenger and strong stand against the American gun culture.
Piers, one of the best known journalistic faces on both sides of the Atlantic, joins MailOnline from CNN where he was host of Piers Morgan Live from 2011 until 2014.
He will write several times each week, bringing his own experience and perspective to bear on the big US stories of the moment.
He will continue contributing a weekly column to the Mail on Sunday newspaper and hosting Piers Morgan’s Life Stories on ITV in Britain.
He will also be pursuing new television ventures in the US.
Piers said of his appointment: “I am very excited to take on the role of Editor-at-Large (US) at MailOnline, which has become the most successful and dynamic platform in the world of news.
“The site is an addictive pleasure, that offers an extraordinarily wide and diverse range of stories from all around the world. It’s become my first stop for news each morning and multiple times throughout the day – as it has for many others, which is why 180 million people now visit MailOnline every month, 60 million of them from here in America alone.
“News should never be boring and MailOnline tells the stories of the day in a compelling, informative and entertaining way that grabs the interest of its readers. As Editor-at-Large (US) I plan on breaking down the biggest stories that matter to Americans and analyzing them in a way that will generate discussion and create debate.
“Writing was my first love as a journalist and being able to write on such a powerful, far-reaching and ambitious global platform is an opportunity I couldn’t turn down.”
Martin Clarke, Publisher and Editor-in-Chief of MailOnline said: “Piers is a fantastic addition to MailOnline.
“He has vast experience as an editor and presenter and certainly knows how to generate conversation and create debate so we’re delighted that he will be joining us as our first ever Editor-at-Large.”