DA MP Stevens Mokgalapa will be announced as the party's new mayor for the City of Tshwane on Sunday.
Mokgalapa, who is currently the party's spokesperson for international relations, was appointed at this weekend's FedEx meeting in Johannesburg.
He will take over from Solly Msimanga who has quit his post to focus on his campaign as DA premier candidate for Gauteng.
Mokgalapa, who is also a former City of Tshwane councillor, confirmed his appointment to TimesLIVE on Saturday evening, but declined to comment further.
"[The party will hold] a formal briefing tomorrow where ...the party will be introducing me. I will [also] be outlining my plan [for Tshwane] as well," said Mokgalapa.
Msimanga was reportedly made to resign last week by the party's FedEx after he was told to choose between being a mayor or the party's premier candidate.