The Welsh Rugby Union Council member takes up the role, which was vacated by former WRU chair Rob Butcher after the recent AGM, with immediate effect.
The new appointment means Manders also joins the WRU Board, also in Butcher’s place.
In addition, Anthony Buchanan and Colin Wilks were re-appointed to the Board at elections held at the same Council meeting earlier this week, following terms ending at the AGM.
Buchanan returns to the position he filled for the 2021-22 season, having previously served between 2014-19, and joins Wilkes in beginning a new three-year term.
The next stage in the governance restructure following the 2022 AGM will be to elect a new WRU chair from within the ranks of the Board – the timeline for this process will be notified shortly with a new WRU chair expected to be in place by the end of the month.