The 59-year-old German -- the first Olympic gold medallist to become president -- won in the second round of voting by his fellow IOC members to beat his five male rivals bidding to succeed Jacques Rogge, who stepped down after 12 years in charge.
Bach, gold medallist with the West German team in the team foil event in the 1976 Olympics, had been the frontrunner throughout the campaign and had for years been seen as the man most likely to replace Rogge.
"Thank you from the bottom of my heart.
"You my friends and colleagues have placed in me an overwhelming sign of trust. I also have enormous respect for my fellow candidates and I will work with you," Bach said.
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"I will put into practise what my motto was during the campaign: 'unity in diversity'."
Bach, a lawyer by profession, is the ultimate insider having been a member since 1991 and has been vice-president three times while also heading up the Judicial Commission.
It had not been all plain sailing for Bach during the campaign with German media in particular posing questions about his ability to be president.
Bach, who has fond memories of Buenos Aires as he and his team-mates came from 7-1 down to win the world foil title in 1975, looked to be in the eye of the storm in August.
An academic report -- commissioned by him -- was released alleging that, like their then East German neighbours, West Germany too had indulged in systematic doping of their athletes.