Infantino is chosen one to rebuild Fifa's image
Gianni Infantino is Fifa's ninth president after being elected at the world governing body's extraordinary congress in Zurich.
The Fifa presidential election entered a second round of voting for the first time in 42 years after Infantino of Switzerland secured more backing than pre-vote favourite Sheikh Salman bin Ibrahim al Khalifa of Bahrain in the first round, when a two-thirds majority was required to win.
A simple majority of more than 50 per cent - 104 votes - was sufficient for victory in the second round.
And Infantino secured 115 votes to Sheikh Salman's 88 to become the second successive Swiss president, after Sepp Blatter.
The Irish FA also backed the 45-year-old lawyer who is from Brig in the Valais region of Switzerland, less than six miles from Blatter's home town of Visp.
Blatter was voted in on five occasions, including last May, but he stepped aside days later amid allegations which led to a six-year ban from football-related activity, which he is contesting.
His resignation prompted the world governing body's extraordinary congress in the most pivotal period of Fifa's 112-year history. Infantino will serve the remaining term of office for which Blatter was elected last May, meaning there will be a further election in 2019.
He said: "Dear friends, I cannot express my feelings in this moment. I told you I went through a journey, an exceptional journey, a journey which made me meet a lot of fantastic people, who love football and breath football and live football every day.
"We will restore the image of Fifa and the respect of Fifa and everyone in the world will applaud us.
"I want to work with all of you together in order to restore and rebuild a new era of Fifa where we can put again football at the centre of the stage.
"Fifa has gone through sad times, moments of crisis, but those times are over.
"We need to implement the reform and implement good governance and transparency.
"We also need to have respect."