[2] Atkinson was the 34th Speaker of the South Australian House of Assembly in the Jay Weatherill government from 2013 to 2018.

He worked as a sub-editor and journalist for the Adelaide Advertiser from 1982 to 1985, an adviser and press secretary to federal minister Chris Hurford from 1985 to 1987, before becoming an advocate for the Shop, Distributive and Allied Employees Association (SDA) in 1989.

On 5 February 2013 Atkinson replaced Lyn Breuer as Speaker of the South Australian House of Assembly.

[9] In a letter on the subject, Atkinson stated, "I don't support the introduction of an R18+ rating for electronic games, chiefly because it will greatly increase the risk of children and vulnerable adults being exposed to damaging images and messages.

[14] In 2009, Atkinson, in his role as attorney-general of South Australia, introduced laws into parliament that made internet commentary on the upcoming 2010 election illegal unless the commenter provided their real name and postcode.

[15] Following public criticism, Atkinson later promised to repeal the section following the 2010 South Australian election and indicated it would not be enforced during the electoral period.

[17] During his time as speaker, Atkinson used his casting vote in Parliament to oppose several bills presented during the Weatherill government.

[21] Atkinson's long-term and current de facto partner is fellow state Labor MP Jennifer Rankine.