Actress Sarah Jessica Parker and Big Apple bookworms are fighting to save the city’s libraries from massive budget cuts with a creative online campaign.

The former “Sex and the City” star kickstarted a petition-like Web site to oppose Mayor de Blasio‘s proposed $11 million funding cut — which would force the New York Public Library system to scale back its hours, programs and days of service — by urging folks to post virtual “sticky notes” telling the mayor why their library branch is “essential.”

“As Carrie Bradshaw might, I couldn’t help but wonder: Can New York City survive without strong public libraries?” Parker wrote in an e-mail encouraging library users to take action.

“Could, I as a New Yorker accept cuts to our wonderful, important, necessary, and beloved libraries? I’m sorry. I can’t,” she said.

The 54-year-old star said her family adores the Jefferson Market Library in Greenwich Village.

“It is not only a regular neighborhood stop for books, programs, and more, it is a cornerstone, a beacon, and one of the most beloved buildings in our community. I don’t know what we’d do without it,” she wrote.

By Sunday, hundreds of people had posted “sticky notes” with their names and that of their neighborhood lit house, including beloved ones in Midtown, Battery City and Yorkville in Manhattan.

“Libraries are the soul of our city!” one woman wrote.

Another user added, “Libraries connect me to a world where anything is possible.”

The proposed budget cuts put forward earlier this year come as city libraries are already struggling, said Angela Montefinise, a senior public-relations director of NYPL.

“The impacts would be especially difficult, as we actually requested $35 million in additional funding this year to cope with rising costs, expanding and new branches to meet that growing needs of New Yorkers,” she said.

The proposed cuts include reducing baseline funding by $3 million and cash from the City Council by $8 million.

They will also likely mean fewer classes and librarians available on-site.

Last month, a poll of more than 1,000 New Yorkers showed that the vast majority — 95 percent — believes the proposed library budget cuts would be a major blow to their neighborhood, according to the polling firm Change Research.