The position was up for nomination until Friday. Doug Beattie resigned from the top job last week following a disagreement with party leaders.
Nine seats in Northern Ireland sent Mr. Nesbitt the necessary 35 signatures.
The 67-year-old will be formally confirmed as leader at a party gathering on September 15th. He is currently Stormont’s health minister.
He was a broadcast journalist before being elected as the MLA for Strangford.
In addition, he will be the first person to lead the UUP twice. He served in that capacity from 2012 until 2017, when he resigned after a challenging election for the Northern Ireland Assembly.
“Continue on the progressive outreach that Doug (Beattie) started,” stated Mr. Nesbitt.
I want to provide the public with a unionist party that is a little more laid back, a little more self-assured, a little more welcoming and inclusive.”
“I want a party that does more than just ask people to vote for us based on who we are. Let’s also discuss policy and what we hope to accomplish for the public.