The Member for the Central Wheatbelt, Mia Davies, has been chosen as the Nationals deputy leader, and will fill the Cabinet position left vacant by the former leader Brendon Grylls.
Mr Grylls announced earlier this month he no longer wanted to continue on as leader of the party, or as the Minister for Regional Development.
National MPs voted on who they wanted to fill the Cabinet spot during a party room meeting today.
They also voted on who would become deputy leader after former deputy, Terry Redman, was declared Mr Grylls' successor last week.
The other nomination for the position was the Member for Kalgoorlie, Wendy Duncan.
In a statement, Ms Davies says her attention will now turn to working alongside Mr Redman ensuring regional WA continued to receive the political consideration it deserved.
She has previously worked as a policy adviser to Brendon Grylls when he was the Regional Development Minister and as an executive officer of the Chamber of Minerals and Energy WA.