On returning to Western Australia, Wittenoom was again elected to the Legislative Council on 12 May 1902, this time for the North Province. He held his seat until 6 November 1906, when he resigned to contest a seat in the Australian Senate in the federal election of 12 December. He stood unsuccessfully as a candidate for the Western Australian Party. He returned to state politics in the following election, winning a North Province seat in the Legislative Council on 13 May 1910. He would hold this seat for 24 years, finally losing after declining to contest the election of 12 May 1934. During this period, he was President of the Legislative Council from 27 July 1922 to 10 August 1926. He also spent a brief period as consul for France in Western Australia.