Sarri was sacked on Saturday after Juventus went out of the Champions League to Lyon on Friday night.
The former Chelsea boss was expected to be relieved of his position after a disappointing season, despite winning the Serie A title.
Juventus have given Pirlo a two-year contract.
There had been speculation that former Juve boss Max Allegri would be appointed, or Spurs' former manager Mauricio Pochettino.
More details to follow
Maurizio Sarri out at Juventus, Mauricio Pochettino or Zinedine Zidane in? - Euro Papers