Arthur Cox is an Irish corporate law firm headquartered in Dublin, with offices in Belfast, London, New York City, and San Francisco.

[11][12] The firm initially benefitted from instructions from Sir Horace Plunkett, South Dublin Unionist Party MP, who Cox had met through a friend's membership of The Arts Club.

[10] The firm was involved in certain aspects of the negotiations of the Anglo-Irish Treaty, with Cox claiming to have traveled to London by mail boat on eight occasions.

[14] Arthur Cox & Co acted as solicitors to the Irish White Cross, set up in 1920 to relieve the distress of the civilian population after the arrival of the Black and Tans.

[23] In response to the COVID-19 pandemic, Arthur Cox announced it would not be paying bonuses to staff and would be "significantly reducing" partnership drawings.