Abrahams, who scored 2 goals in nine first-team appearances for the O’s last season, has joined the Canaries for an undisclosed fee.
The 18-year-old will remain in E10 for this season, however, following an agreement between both sides to loan the forward back to Orient for the 2017/18 campaign.
As part of the agreement, Abrahams will also be able to train with and feature for Norwich`s under-23 side.
Having penned his first professional deal in November 2016, Abrahams made his O’s debut as a substitute at Newport County on March 4th before scoring his first senior goal in a 2-2 draw at Luton Town on April 14th.
Abrahams told the O`s official website “Signing for Norwich is a great opportunity and what I believe to be the right move for my career.
“Orient is a club that I will always hold close to my heart and I am extremely grateful for the help and support I have been given from such a young age.
“I was handed a fantastic chance last season in difficult circumstances, but the fans were so supportive during that time and I would like to thank them for that.
“I am pleased to be staying here on loan, and while I continue to wear the shirt I will give everything I have got to this Football Club.”
Abrahams` sale follows hot on the heels of Steven Alzate`s move to Premier League newcomers Steven Alzate (see separate news item).