ALSO READ: Williams sisters to team up at French Open
Former world number one Williams, now ranked a lowly 453, is playing a Grand Slam for the first time since she won her 23rd major at the 2017 Australian Open after which she stepped off the tour to give birth to her daughter in September.
Pliskova, the twin sister of world number six Karolina, has never won a main draw match at Roland Garros.
Williams has played just four matches on the tour in 2018 and not featured at all since Miami in March.
Sharapova, champion in 2012 and 2014, could face Serena in the fourth round.
The Russian who missed last year’s event after she was refused a wild card as she battled to rebuild her career following a 15-month doping ban, has not defeated Williams since 2004.
Top seed and two-time runner-up Simona Halep faces Alison Riske of the United States in her opener while second seed and Australian Open champion Caroline Wozniacki starts against another American, Danielle Collins.