Mr Gageler replaces Justice Bill Gummow, who will leave the bench in October when he reaches the compulsory retirement age of 70.

Attorney-General Nicola Roxon has declared she is determined to cast the widest net for the nation's top judges.

Earlier this year, she wrote to the states, law societies, universities and community legal centres seeking nominations.

She said she was seeking greater diversity  including in the attributes of  gender, professional background, geography and cultural background.

''What I want is that people don't think they can only nominate a commercial barrister from Sydney — who's a man,'' Ms Roxon told The Age in March.

''I believe that Stephen is the best person for the job,'' Ms Roxon said today.

Ms Roxon thanked Mr Gageler for his work as the Solicitor-General and congratulated him on his appointment.

‘‘It is a role that he will fill with distinction,’’ she said in a statement.