Senior banker Tony Wild formally becomes a member of the Legislative Council this morning (Tuesday).
Mr Wild, who polled 16 votes in yesterday's election, will be sworn in by Deemster David Doyle.
He comfortably defeated Arbory commissioner Brian Rae in a contest for the seat made vacant following Clare Christian's election as president of Tynwald, at the July sitting.
Mr Wild, who has been head of priority services at Standard Bank, will serve as an MLC until February 2013.
The swearing-in ceremony is at a special sitting of LegCo at 9.30am.