Steenhuisen was announced as the successful candidate, following the DA’s federal council meeting, held at the party’s headquarters in Bruma, Johannesburg.
The position of DA leader was left vacant after Mmusi Maimane suddenly resigned last month and terminated his membership, leaving the party without a top dog.
Maimane’s resignation also saw Athol Trollip resigning as party federal chairperson.
Western Cape agriculture MEC, Ivan Meyer, has been elected as the new interim federal chairperson to replace Trollip.
Since the dramatic election of federal council chairperson Helen Zille last month, the DA has been rocked by leadership instability and political uncertainty as some were opposed to her return to DA.
The controversial Zille led the party from 2007 to 2015.
Those who did not see eye-to-eye with Zille included Maimane and Trollip.
Johannesburg mayor Herman Mashaba announced his resignation from his position and his decision to cancel his membership of the DA shortly after her election.
Mashaba is set to leave his post on November 27.
Steenhuisen will assume the task of leading the party towards its federal congress in April, where the party will make a fresh leadership selection.
Speaking after his election, Steenhuisen said the DA was not in a fight over ideology or a fight for power, but to turn the tide of poverty in South Africa: “Our fight is for the prosperity and the dignity of millions.”