Mr Alexander, who first took the role in an interim capacity in 2016 (following the resignation of incumbent, Mr Oregan Hoskins) was nominated by representatives of 11 SARU’s member unions.
He will formally begin his third and final full term at the Annual General Meeting in Cape Town on 14 May.
Meanwhile eight nominations were received for the two open positions on the SARU Executive Council.
The current holders of the roles, Mr Hennie Baartman and Mr Randall September, are standing for election for a second term but are opposed (in alphabetical order) by Adv Zuko Badli (nominated by Border), Ms Zelda Freitag (Mpumalanga), Ms Mimi Tau (Blue Bulls), Ms Mpho Sekulisa (Free State), Mr Ryno Opperman (Free State), and Ms Tania Vermaak (Eastern Province).
It is a requirement of the SARU constitution that at least one of the two members to secure election is a woman.