Varadkar, the son of an Indian-born father and Irish mother, became a doctor before first entering Irish parliament at the age of 27. He was speaking on the radio on his 36th birthday when he said, "I am a gay man".
Varadkar, who now serves as minister for social protection, will officially be confirmed as prime minister when the Irish parliament reconvenes on June 13, according to CNN. He campaigned on same-sex marriage and liberalising abortion laws, although like the majority of his party colleagues, he is an advocate of tight fiscal restraint.
Varadkar is now the minister for social protection and has earned a reputation as a candid politician.
It comes after Enda Kenny stood down as taoiseach, or Prime Minister, and the leader of the party. Kenny did say he would continue to serve until a replacement was elected.
"Ireland, a devoutly Catholic country that decriminalised homosexuality only 24 years ago, is poised to elect its first openly gay prime minister next month", wrote the New York Post.
And so every proud parent in Ireland today can dream big dreams for their children; every boy and girl can know that there is no limits to their ambition, to their possibilities, if they are given the opportunity.
"It is a sign of how much Ireland has changed and moved on that no one really cares if he is gay here".
Varadkar made all the running in the race to become next party leader, attracting many early public endorsements from high-profile members of his party.
If confirmed as prime minister, Varadkar will lead a country still emerging from the shadow of the 2008 global financial crisis, which hit the debt-fueled "Celtic Tiger" economy particularly hard. Other previous world leaders were former Belgian Prime Minister Elio Di Rupo and former Icelandic Prime Minister Jóhanna Sigurõardóttir.