Gunners' manager Mikel Arteta had been eager to bring in experienced players to strengthen the team. With Thomas Partey also departing, Norgaard's arrival is seen as a positive move for the club.
The Bees' captain leaves Brentford with their best wishes, with new manager Keith Andrews expressing his support for the midfielder's decision to join a bigger club.
It's understood that Arsenal will pay £9m for Norgaard's transfer, bringing an end to his time with Brentford.
