Louis Tomlinson's mother Johannah Deakin passed away on Wednesday after suffering from leukaemia.
Following the sad news of the mother-of-seven's passing at age 43, stars and fans have come out to send their messages of condolence and support for the One Direction star.
Leading the tributes was pop star Cheryl, who knows Louis from his X Factor days and who is currently dating his One Direction co-star Liam Payne.
She wrote: "@Louis_Tomlinson my heart breaks for you. I am so sorry. My thoughts are with you and your loved ones at this incredibly tragic time."
Zayn Malik, Louis' former One Direction bandmate, followed this up with: "@Louis_Tomlinson love you bro! All of your family is in my prayers. proud of your strength and know your mum is too x."
Other stars from across the entertainment industry sent messages of condolence to Louis and his family.
The Wanted's Nathan Sykes wrote: "Thoughts are with @Louis_Tomlinson today. Heartbreaking news."
Boyzone star Ronan Keating posted on Twitter: "My Heart goes out to Louis Tomlinson and his family at this time. Heartbreaking."
The likes of Piers Morgan, Rebekah Vardy, Stevi Ritchie and Dannielle Armstrong of TOWIE fame also wrote messages for the star.
Johannah had been cared for at University College London hospital since May before being moved to the Royal Hallamshire Hospital in Sheffield for the last few weeks of her life.
In a statement issued by Louis's representative, her family said: "It is with immeasurable sadness that Johannah Deakin's family said goodbye to Johannah in the early hours of Wednesday 7th December 2016.
"Earlier this year Johannah was diagnosed with a very aggressive form of leukaemia that required immediate and continuous treatment. We respectfully request that the family are given time and space to grieve in private."
Her husband, Dan Deakin, paid tribute, calling her "incredibly selfless" and a "truly amazing mother".
As well as 24-year-old Louis, she leaves behind six other children, Lottie, 18, Felicite, 16, and two sets of twins, Phoebe and Daisy, 12, and two-year-olds Ernest and Doris.
In a 2012 interview, Louis said he and his mother were "best friends".
She was born Johannah Poulston on March 25, 1973.
In 1991, aged 18, she and first husband Troy Austin welcomed the future pop singer into the world.
After the pair divorced when he was a toddler, she married Mark Tomlinson.
The couple had four children but split up as One Direction found X Factor fame.
Two years ago, she married Mr Deakin and gave birth to a second set of twins.
She became a grandmother for the first time in January when Louis's son Freddie Reign was born to Los Angeles-based stylist Briana Jungwirth.