The Russian, 30, was ranked too low to gain direct entry as she continues her return from a 15-month drugs ban.
“There can be a wildcard for the return from injuries – there cannot be a wildcard for the return from doping,” French Tennis Federation chief Bernard Giudicelli Ferrandini said.
The French Open begins on 28 May.
Sharapova had been hoping to receive a wildcard either into the main draw or the qualifying tournament.
“I’m very sorry for Maria, very sorry for her fans,” added Giudicelli Ferrandini.
“They might be very disappointed, she might be very disappointed, but it’s my responsibility, my mission, to protect the high standards of the game played without any doubt on the result.”
The former world number one has not played a Grand Slam since she tested positive for heart disease drug meldonium at the 2016 Australian Open.
That brought an initial two-year ban, later reduced to 15 months after the Court of Arbitration for Sport found she was not an “intentional doper”.
Sharapova returned to action without a ranking last month and has since risen to 211 in the world after receiving wildcards in Stuttgart, Madrid and Rome.
That will be enough to at least earn a qualifying spot at Wimbledon next month.
She could yet qualify directly for the main draw with a good run at this week’s Italian Open, otherwise Wimbledon will announce on 20 June whether the Russian is among the wildcards at the All England Club.
