City top the standings on 52 points with 21 of their 22 games played. Arsenal needed to win all of their remaining four games to have any chance of stealing top spot, but Brighton held them to a stalemate to send the title to the north-west, instead of North London.
Having made it to the Champions League semi-finals before being knocked out by OL Lyonnes last weekend, Arsenal came into Wednesday's game against Brighton with a considerable task ahead of them if they were to threaten City, but they went behind when Fuka Tsunoda scored just before the break.
Norwegian midfielder Frida Maanum pulled a goal back on the hour mark, but despite a late surge Arsenal couldn't find a winner.