Bill Walker, 71, was found guilty at Edinburgh Sheriff Court last month of 23 charges of assault against his three ex-wives and a former step-daughter from 1967 to 1995.
The Dunfermline MSP has refused to resign his seat despite public pressure and a motion signed by at least 90 MSPs demanding his immediate departure from the Scottish Parliament.
Members and supporters of Scottish Women's Aid, NUS Scotland Women's Campaign and Zero Tolerance gathered for a rally outside Holyrood this afternoon as MSPs returned from their summer break.
One of the organisers, Stacey Devine, NUS Scotland women's officer, said resigning is the "only decent thing" Walker can do.
"We're here to send a clear-cut message to Bill Walker that he's not fit for office and that he should not have the privilege of actually representing the people of Fife and the people of Scotland," she said.
"Violence against women is a serious crime. Violence against women must end and Bill Walker must resign.
"He's a disgrace and he should be ashamed of himself."
Ms Devine also said questions are to be asked about why the case was prosecuted at summary level without a jury, a procedure which restricts the sheriff's sentencing power.
Jenny Kemp, coordinator for Zero Tolerance, said there is a strong feeling in Scotland that Walker is not fit for office and that he should resign as an MSP.
"We're here for three reasons. One, to send that very strong message to Mr Walker: you are not fit to be an MSP. Your presence in the Parliament demeans it. Mr Walker, you have no integrity. You must resign," she told the rally.
"The second reason that we're here is to show that the Parliament's procedures are not fit for purpose and they must change. We need the Parliament, which is full of creative intelligent minds, to be thinking of whatever ways it can, whatever means it has at its disposal, to ask Mr Walker to resign."
Scotland has some way to go in developing a zero-tolerance culture towards domestic abuse, Ms Kemp told the gathering.
"Mr Walker is just one individual. There are thousands of individuals in Scotland who perpetrate domestic abuse and thousands of women who live with that experience.
"We need to send out a message to them that we care, that we believe you, that we support you and that you deserve justice."