He said Goldman Sachs was "one of the main institutions" involved in selling subprime debt, and also noted the U.S. bank's role helping Greece establish credibility about its finances in the early 2000s. Worries about Greek debt later rocked the currency bloc.
"It's not about Europe, it's about morality," said Hollande in his annual interview to mark Bastille day, France's national day.
"Legally, it's possible, but morally, it's about the person, it's morally unacceptable."
The bank said earlier this month it had hired Barroso, a conservative Portuguese ex-premier who headed the European Union's executive arm from 2004-2014, to be an adviser and non-executive chairman of its international business.
Barroso was hired 20 months after stepping down, shortly after an 18-month "cooling off" period when ex-commissioners must seek clearance for new jobs to avoid conflicts of interest.
Earlier this week the French government called on Barroso to walk away from the job and the European Ombudsman called for the EU to tighten rules on commissioners taking appointments on leaving office.
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