Russo joined United in 2020 under former manager Casey Stoney following two years in the United States at the University of North Carolina.
She was United’s joint-top scorer in the Women’s Super League (WSL) this season with 10 goals and one assist in 20 matches as they finished runners-up in the league – their highest ever finish, which ensured qualification for next season’s Champions League.
The centre-forward was a breakout star at Euro 2022, coming off the bench to score four times, including a memorable backheel in the semi-finals, as England won their first women’s major tournament.
There is competition in the Arsenal squad for attacking positions with England’s Beth Mead, the Netherlands’ Vivianne Miedema – both recovering from anterior cruciate ligament injuries – Australia’s Caitlin Foord and Swedish pair Stina Blackstenius and Lina Hurtig already on the books.
Russo will join her Arsenal team-mates after the Women’s World Cup, which kicks off in Australia and New Zealand on 20 July.
The new WSL season starts over the weekend of 29 September to 1 October.