The "Game of Thrones" star, 24, took to Instagram alongside husband Joe Jonas as the two remain in isolation at home and, though she did not name the 40-year-old "Avengers: Endgame" actress, Sophie made the subject of her comments clear.
"Here's the tea," she said, while holding her own mug of tea. "Stay inside. Don't be f**king stupid, even if you count your 'freedom' over... your health."
Sophie continued: "I don't give a fffffff about your freedom. You could be infecting other people, other vulnerable people around you by doing this! So stay inside guys. It's not cool and it's not big and it's not clever. And that's the tea."
The star's furious rant comes after Lily insisted it was "business as usual", despite the fact she's "immunocompromised" and at a high risk from COVID-19.
Responding to fans who slammed the star's carefree attitude after she said she had, "just dropped my kids off at gymnastics camp," Lily added: "I am also immune compromised (sic) at the moment. I have two young kids. Some people value their lives over freedom, some people value freedom over their lives. We all make our choices."
The World Health Organisation (WHO) has issued guidelines relating to the virus and is advising people to practice social distancing and stay at home in a bid to prevent the spread of COVID-19.
The outbreak of coronavirus has seen more than 328,000 cases of the virus registered worldwide, resulting in a death toll of over 14,300, since it began in December (19).