Felicite Tomlinson passed away on Wednesday in London in the United Kingdom, according to TMZ.
While nothing has been officially confirmed, TMZ is reporting that she was found deceased at her home in the Earls Court area of West London, England on Wednesday (March 13).
Felicite - who was known as Fizzy - was an aspiring fashion designer and influencer with over a million followers on Instagram.
This tragic news comes three years after Louis and Felicite's mum Johannah died of Leukaemia.
I have £70,000 in savings. How can I retire in 15 years with an income of £25,000 a year?’ Money
Louis has not spoken publicly about this devastating news at this time.
One Direction star Louis Tomlinson is said to be "devastated and distraught" by the passing of his sister.
Louis Tomlinson back in 2014 taking selfies with fans.
At the time he described the performance as "harder than I ever imagined". We sent two ambulance crews, a single responder in a auto and an advanced paramedic to the scene. Currently, The Sun says the young woman's death is being classified as "unexplained" by authorities, pending a full autopsy and toxicology test.