The changes to the page, which shows pieces of information about alleged corruption within the party blacked out, were made following the passing of the controversial protection of state information bill on Tuesday.
Party spokesperson Keith Khoza said: "It's conduct that it not consistent with a civilised... society.
"How does that assist any cause or anybody to tamper with information?"
Wikipedia allows any internet user to edit or change their pages.
"Interfering with information undermines the very need of [information providers]," Khoza said.
He said that the party wanted whatever information was on the page to be restored, even if it showed the ANC in a negative light.
Civil society organisations and members of the media reacted with outrage following the passing of the bill on Tuesday. They promised that they would engage in acts of civil disobedience and would go to the Constitutional Court to have a public interest clause put into the bill.