Anna Lo was insulted after calling for flags and paramilitary murals glorifying gunmen to be removed from the route of this year's cycling race, which will begin in the region for the first time this spring.
She represents the cross-community Alliance Party in South Belfast at the Stormont Assembly. The abuse was posted on social media sites over the past 24 hours, a party spokesman said.
A senior Democratic Unionist Party minister in the power-sharing executive at the devolved administration has separately defended the painting of non-paramilitary wall murals along the route of one of the world's largest international sports events.
Ms Lo said: "I am very disappointed that people (on social media) would react in such a personal way and use abusive and very personal comments against me.
"What I was talking about was a public issue and I speak for a lot of people who are sick and tired of flags being hung on lamp posts and left there for months and months to become tattered.
"Many, many people in those areas would not want to see a mural glorifying violence and intimidation."
Ms Lo's party colleague Stewart Dickson said he was disgusted by vile remarks from social media users.
"The people who made these comments are bringing shame to Northern Ireland and do not represent the vast majority of the population who have welcomed people from all backgrounds," he said.
"As a society we can do so much better for everyone by working together."
Hong Kong-born Ms Lo appealed for a flag and mural-free race after Stormont Environment Minister Mark Durkan said no election posters should be erected along the Giro route from May 9-11.
European and local council elections are being held later that month.
The Giro is expected to be watched by hundreds of millions of viewers and some local politicians believe the sight of paramilitary murals and flags which have sparked serious sectarian division and rioting would be bad for the image of Northern Ireland. A time trial is scheduled through a mainly loyalist inner city part of east Belfast.
Ms Lo is Alliance's candidate for Europe and said the arguments which politicians have been making about taking down election posters also applied to flags and murals.
She said earlier this week: "Funding will be made available in towns along the route to improve the image of eyesores such as derelict buildings but I have a bigger problem with images of paramilitary gunmen.
"Do we really want these images to be visible on the route when millions of people will be watching the race on television."
Her comments prompted loyalist abuse on Facebook.
Meanwhile, Democratic Unionist Enterprise Minister Arlene Foster defended the painting of non-paramilitary murals, which can involve images of former Manchester United football great George Best in his heyday or the East Belfast shipyard which built the Titanic.
"Murals are part of a cultural expression right across Belfast and right across Northern Ireland," she told the Assembly.
"It would be sad if visitors to Northern Ireland could not engage in appreciating the rich cultural heritage that we have in Northern Ireland."
Democratic Unionist MP Sammy Wilson said local communities supported the Giro and were excited to welcome the event to their neighbourhood.
"Rather than sitting in judgement on communities, the Alliance Party should set their policy of building an anaemic society to the side and work with communities to influence change in the longer term," he said.
"I don't like to see tattered Union flags flying anywhere but for as long as the Alliance Party and others block the Union flag being flown in its proper place on civic buildings then they have little grounds for lecturing communities how they display their national flag."