Rebel Wilson is being sued for defamation after attacking the wrong person on Twitter.

Seven months after attacking the wrong Elizabeth Wilson on Twitter, Australian comedian Rebel Wilson is being sued for defamation.

The online argument was sparked in late February when Wilson learned that a journalist named Elizabeth Wilson had visited her elderly grandmother’s house to ask questions about the star. A series of abusive tweets about her family’s invasion of privacy quickly followed.

Enraged at the ‘harassment’, Wilson launched a series of abusive tweets aimed at the journalist.

Rebel Wilson's initial tweet about Elizbeth Wilson. Source: Twitter.

"If your name is Elizabeth Wilson and you work for ACP Magazines, just know you are a disgrace for harassing my sweet, sick grandma," the 36-year-old tweeted.

The Pitch Perfect star continued to fire off tweets about the reporter to her 2.43 million followers, one of which included a headshot of House and Garden Magazine's Elizabeth Wilson and the caption "Here she is: total scum".

Another tweet read: "Her actions are so disgraceful and upsetting and she should be shamed for this conduct. Authorities have been contacted."

Wilson then tweeted a headshot of the wrong Elizabeth Wilson. Mamamia has pixelated Wilson's face for privacy. Source: Twitter.

The problem was, Rebel had the wrong Elizabeth Wilson.

The Elizabeth Wilson who had appeared at (and was welcomed into) her grandmother's house was freelance features writer Elizabeth (Lizzie) Wilson.

And when numerous Twitter users and media outlets (including Mamamia) contacted Rebel to point out that she was attacking the wrong journalist, Rebel refused to take the photo down for a number of hours responding, “Well send me a picture of the right Elizabeth Wilson”.

Wilson remained unapologetic. Source: Twitter.

Now months on from the saga, Elizabeth Wilson is taking legal action, suing the Los Angeles-based actress for damages and aggravated damages, explaining in a statement to the NSW Supreme Court that Wilson labelling her a “low, despicable and worthless person” who “repeatedly harasses people" has had an adverse effect on her wellbeing.

It is not known how much Elizabeth Wilson is seeking in damages from the comedienne, but according to the Daily Telegraph, the losing party in NSW defamation suits can be ordered to pay up to $2 million to cover legal costs and damages.

Rebel Wilson is yet to publicly respond.