Uefa's general secretary secured 115 votes in the second round of polls, beating off favourite Salman Bin Ibrahim al-Khalifa into second while Prince Ali bin Hussein finished third.
Infantino succeeds the dethroned Sepp Blatter, who was suspended from all football activities for eight years - later reduced to six - along with ex-Uefa president Michel Platini for corruption.
Truly humbled by today's decision. Let's bring FIFA forward together.— Gianni Infantino (@Gianni_2016) February 26, 2016
"I told you I went through a journey, an exceptional journey, a journey which made me meet many fantastic people, many people who love, live, breathe football every day.
"Everyone has to be proud of what we will do at Fifa. I want to thank you all, all 209 and the other candidates. Tokyo [Sexwale] decided four can win, one cannot win. We had a great competition, a great sign of democracy in Fifa.
"I want to be president of all 209 [member federations]. I have travelled the globe and I will continue to do this. I want to work with all of you together in order to restore and rebuild a new Fifa where we can put again football at the centre of the stage."