Suffragan bishop-elect Robertson, 45, and his partner Mohan have two children. He is the incumbent of Christ Church, Deer Park, in Toronto, and was ordained deacon and priest in 1997 after earning his Master of Divinity from Trinity College in Toronto.
"I'm very overwhelmed," he said on the chancel steps after his election. "I didn't really expect to be standing here on the steps, but I'm deeply, deeply honoured. I realise this is an historic day in the life of our church. It's no secret that I'm the first openly gay, partnered bishop-elect in the diocese and perhaps in the Canadian church as well, and I know that for some people that's a real challenge and for others it's the fulfilment of what they've been hoping and praying for a very long time. The peace and unity of the church is really important to me and I will work to continue that peace and unity as a bishop."
Robertson's election is not without criticism.
Before the election, the Rev. Dr. Catherine Sider Hamilton of St. Matthew's Riverdale in Toronto issued an official protest against the inclusion of "one candidate whose lifestyle is, to the best of my knowledge, irregular according to the teaching of the church regarding chastity and marriage".
She went on: "It is a teaching that still stands formally, and I believe that the inclusion of this candidate by the nominations committee is premature."
The Archbishop of Toronto, Colin Johnson replied that all the nominees were clergy under license in the diocese and in good standing.
Robertson said his election was "a turning point for our diocese, and I'm honoured to be a part of that."
He added that though his election reflected inclusivity in the Church, he also wanted to represent the whole Church.
"I think LGBTQ clergy and lay people might naturally gravitate towards me looking for some leadership around the issue of full inclusion, but I absolutely see myself as a bishop for the whole church, including people who have a very different view of things than I do. I'm their bishop, too."
Archbishop Johnson said: "Kevin is certainly not the first gay man to become a bishop in the Communion but his election will probably bring a negative reaction in some places and a positive reaction in others. We're at an early stage in this experience. I think many parts of the world do not understand it, so it will be a challenge for them, but it will be an opportunity for us to explain how and why we have made this choice".
The Anglican Church in Canada first began accepting same-sex unions in 2002. Canada nationally legalised same-sex marriage in 2005.