"But it is now all too common to hear calls for swift and severe retribution in response to perceived transgressions of speech and thought.
"We are already paying the price in greater risk aversion among writers, artists, and journalists who fear for their livelihoods if they depart from the consensus, or even lack sufficient zeal in agreement.
"As writers, we need a culture that leaves us room for experimentation, risk-taking, and even mistakes. We need to preserve the possibility of good-faith disagreement without dire professional consequences.
"Editors are fired for running controversial pieces; books are withdrawn for alleged inauthenticity; journalists are barred from writing on certain topics; professors are investigated for quoting works of literature in class; a researcher is fired for circulating a peer-reviewed academic study; and the heads of organisations are ousted for what are sometimes just clumsy mistakes."
Rowling shared a link to the article on Twitter and wrote: "I was very proud to sign this letter in defence of a foundational principle of a liberal society: open debate and freedom of thought and speech."
Her involvement with the open letter comes after she faced criticism for invalidating transgender people, when she took to Twitter to slam an article for using the phrase "people who menstruate" rather than "women".
She later shared a personal essay on her website, in which she doubled down on her beliefs and was also recently condemned for comparing transgender hormone replacement to gay conversion therapy.