Ant McPartlin said Father Dermot Donnelly was “the kindest and wisest man I knew” and “will never be forgotten” following his death aged 55.
McPartlin, 46, wrote on Twitter: “Father Dermot, you were the kindest and wisest man I knew. Rest in peace my friend. You will never be forgotten.
“My thoughts, prayers and love are with your wonderful family. The world has lost a special person. X A.”
The Diocese of Hexham and Newcastle was the first to announce the news of Fr Dermot’s death on Friday afternoon – with Declan, 46, paying tribute to his brother shortly afterwards.
He tweeted: “It is with a broken heart that I inform you that my dear brother Fr Dermot, @TweeterPriest has sadly passed away this afternoon.
“We are all beyond devastated.
“Thank you for your messages of sympathy and support, they are appreciated DD.”
In 2015, Father Dermot officiated at his brother’s wedding to Ali Astall in Newcastle in a star-studded ceremony.
A statement from the Diocese of Hexham and Newcastle said: “It is with great sadness that we have to inform you of the death of Father Dermot Donnelly, who passed away peacefully this afternoon in hospital.
“It was a big shock for all of us.
“Pray for the repose of his soul and keep his family, especially his mother, in your prayers at this difficult time.”
Father Dermot recently celebrated his 30th year of service to his parish and community, where he was best known for his work with youth and youth ministry.
He was a member of the clergy of St. Joseph’s Church, Stanley, County Durham.