Dathan Paterno's resignation was effective immediately following his Sunday tweets from his personal Twitter account, according to the school district.
READ: DATHAN PATERNO'S RESIGNATION LETTER
In his resignation letter, Paterno admits "provocative tweets" about the marches, which drew millions of demonstrators on Saturday across the country and globe. A protest in Chicago drew tens of thousands of people.
His tweets were apparently were directed at some of the women in the march who were dressed in anatomically correct costumes.
Parents learned of the resignation in an email from the district Monday morning. Many plan to attend a regularly scheduled school board meeting Monday night to talk about the issue.
Some parents said he had the right to make the comments, while others thought it was inappropriate.
The district believed the tweets reflected on the district.
In a statement, the district said: "We find it truly unfortunate that his personal views have become connected to the important work we are doing here in District 64 ... Please know that his comments do not reflect those of the Board. Some parents however disagree with his resignation."
Paterno said: "In retrospect, they were inappropriate and pushed too far in some ways. While I merely meant to harshly criticize some of the protestors (especially the very angry, hostile, vulgar, and violent ones) and question the motives of some of them, my tweets were understandably misinterpreted to mean that I disrespect or hate all the protestors. Of course, this isn't true, but the damage was done."
Paterno's four-year term expired in the spring. The board will fill the vacancy.
Paterno, whose psychology office is down the street from the school board office, did not respond to ABC7's requests for comment on Monday.