Nominated Senator Naisula Lesuuda is the first Samburu woman to win an elective post on first try.
The former news anchor will take over from Jonathan Lelelit as Samburu West Member of Parliament.
Lesuuda beat cultural odds by campaigning in a male-dominated county which has not fully embraced leadership by women.
Some 14,560 constituents voted for her, compared to the 13,970 who wanted Leleit to return to office.
The outgoing legislator had been termed a political heavyweight and Lesuuda confirmed the race was not easy.
"To my very worthy competitor...it was not an easy battle...it has not been easy. I ask our supporters to embrace each other as brothers and sisters...let us all work together," she said on Thursday.
The politician asked her supporters to welcome those of Lelelit to celebrations so they see that the change she will steer will also be to their benefit.
While receiving her election certificate at AIC Moi Girls' Secondary School, Lesuuda promised her leadership will be all-round.
"While campaigning I said our win would be for the glory and honor of God."
She added that this is just her first step as much more is in store in terms of service to Samburu West residents.