The protester jumped up on the table in front of Draghi, wearing a shirt calling for the end of the "ECB dick-tatorship."
The protester also appeared to dump white paper confetti on the central bank chief.
Security wrestled the woman away, and she was reportedly removed from the premises.
Draghi was just beginning to speak about the European economy when the protester rushed the stage.
ECB security is "investigating the disruption," according to a representative for the central bank who declined to comment further.
An official statement from the ECB praised its security staff for "immediate and effective action."
"Initial findings suggest that the activist registered as journalist for a news organisation she does not represent. Like all visitors to the ECB, she went through an identity check, metal detector and x-ray of her bag, before entering the building," the statement said, adding that Draghi "calmly" proceeded with the press conference after the disruption.
The protester was apparently Josephine Witt, who posted about the experience on the Twitter later on Wedhesday.
Below is a sequence of the protest:
—CNBC's Matt Clinch contributed reporting.