Gradon's cause of death remains unknown, but it's believed the star had been battling depression for several years.
Her boyfriend Aron Armstrong wrote on Facebook saying: "I will never forget that smile I love you so so much baby your my world forever and always".
The couple was recently vacationing in the resort town of Antibes in southern France to celebrate Armstrong's birthday.
The 38-year-old took to Twitter to pay her respects to the the 32-year-old former Miss Great Britain, who was found dead in her home on Thursday. "I'm so lucky to have met you", Buckland wrote.
As the show started, viewers saw a blank black screen appear with a profile picture of Sophie Gradon from the time she was in the villa.
She tweeted: "You were such an intricate, creative, intelligent soul".
"So very sad. Such a attractive soul. such a attractive smile.thoughts and love with friends and family", Flack wrote. "RIP" Fellow Islander Cara de la Hoyde posted: "Such a bad day my heart is broken & goes out to the very one effected". I can not work out what to say.
The series 2 contestant died this week aged 32. "Shocked beyond belief! RIP [Sophie Gradon] sending all our love to Sophie's family at this incredibly sad time", a tweet from the organization read. RIP you handsome attractive woman.
Sophie Gradon's best Instagram pics.
The official Love Island Twitter account posted a statement after the news about Sophie broke earlier today.
Olivia Buckland, who also appeared, wrote: "Awful very bad news this morning. My gorgeous girl, why".