Faye White's Borehamwood-based side picked up the trophy in front of a record attendance (24,582) for the final at Forest's City Ground.
A close goalless opening 45 minutes was followed by a more open second half, with the Gunners' goals coming from Kelly Smith (2), Jayne Ludlow and Lianne Sanderson, as Leeds' goalkeeper Carly Telford's heroic performance failed to keep Arsenal at bay.
Jessica Clarke headed Leeds back into the game at 1-3 but Smith tapped in a fourth to secure a record ninth FA Cup triumph for the Gunners. The result handed Arsenal a hat-trick of league and cup doubles.
Arsenal: 1 Emma Byrne, 2 Alex Scott, 4 Jayne Ludlow, 6 Faye White (c), 7 Ciara Grant (3 Yvonne Tracy 74), 8 Kelly Smith, 9 Lianne Sanderson (10 Julie Fleeting 74), 11 Rachel Yankey (12 Gemma Davison 74), 14 Karen Carney, 18 Anita Asante, 23 Mary Phillip.
Unused Subs: 13 Rebecca Spencer, 15 Gilly Flaherty.
Leeds United: 1 Carly Telford, 2 Sophie Bradley, 5 Jess Wright (c) (23 Gemma Bonner 86), 6 Katie Holtham, 8 Sue Smith, 9 Steph Houghton, 12 Jess Clarke, 14 Jade Moore (19 Mel Sutcliffe 60), 16 Amanda Barr, 17 Alex Culvin (20 Olivia Thackray) , 18 Sophie Walton.
Unused Subs: 13 Emma Higgins, 21 Ashley Hutton.
A close goalless opening 45 minutes was followed by a more open second half, with the Gunners' goals coming from Kelly Smith (2), Jayne Ludlow and Lianne Sanderson, as Leeds' goalkeeper Carly Telford's heroic performance failed to keep Arsenal at bay.
Jessica Clarke headed Leeds back into the game at 1-3 but Smith tapped in a fourth to secure a record ninth FA Cup triumph for the Gunners. The result handed Arsenal a hat-trick of league and cup doubles.
Arsenal: 1 Emma Byrne, 2 Alex Scott, 4 Jayne Ludlow, 6 Faye White (c), 7 Ciara Grant (3 Yvonne Tracy 74), 8 Kelly Smith, 9 Lianne Sanderson (10 Julie Fleeting 74), 11 Rachel Yankey (12 Gemma Davison 74), 14 Karen Carney, 18 Anita Asante, 23 Mary Phillip.
Unused Subs: 13 Rebecca Spencer, 15 Gilly Flaherty.
Leeds United: 1 Carly Telford, 2 Sophie Bradley, 5 Jess Wright (c) (23 Gemma Bonner 86), 6 Katie Holtham, 8 Sue Smith, 9 Steph Houghton, 12 Jess Clarke, 14 Jade Moore (19 Mel Sutcliffe 60), 16 Amanda Barr, 17 Alex Culvin (20 Olivia Thackray) , 18 Sophie Walton.
Unused Subs: 13 Emma Higgins, 21 Ashley Hutton.