Bartoli, the 2011 champion on the English south coast, pulled out with a viral infection, she said in a statement.
"I'm really disappointed to have to withdraw, since it's so nice here and I've always done well at this tournament," she said.
"I have a virus and a fever and am really feeling terrible. I started feeling this way on Monday but it has gotten worse.
"I'm hoping to be back on the court after a few days of rest to get ready for Wimbledon."
Bartoli was ranked 15th for Wimbledon in the seedings announced by competition organisers on Wednesday.
The Grand Slam grasscourt tournament begins on June 24 and ends on July 7.