Blanc, 56, was appointed by Lyon on Sunday on a deal to the end of next season following the sacking of Dutchman Peter Bosz.
Lyon, won seven consecutive French titles between 2002 and 2008, have drifted into mediocrity under Bosz and finished eighth in Ligue 1 last season, failing to qualify for Europe for the second time in three campaigns.
Blanc now takes over a side who sit ninth in the table after just 10 matches, 12 points behind leaders PSG having taken just a single point from their last five outings.
They are also a club in limbo off the field, with a planned takeover by American businessman John Textor still to be completed.
"I have that desire, and this sport, in my heart and soul, so I was open to all offers," said Blanc, who left PSG in 2016 having led them to three straight Ligue 1 titles.