Flowers in the shape of a musical note and the words Unforgettable, That's What You Are adorned the coffin of David Gest as stars including Kerry Katona, Kym Marsh and Darren Day gathered for his funeral.
Gest, 62, was a music producer and the former husband of Liza Minnelli.
He was found dead in a five-star hotel in London on April 12.
Denise Welch, Danniella Westbrook, Gemma Collins, Lizzie Cundy, Vanessa Feltz and Dean Gaffney were also among the mourners at his funeral at Golders Green Crematorium.
A wooden coffin with gold handles and adorned with white flowers arrived in a hearse for the ceremony.
A white floral display with a black musical note, a butterfly and the lyrics to Nat King Cole's famous song rested alongside it.
Mourners embraced and talked quietly as they waited to go inside the chapel.
One attendee could be seen sobbing and was consoled by other guests.
The American TV personality gained a following in the UK for his appearances on Celebrity Big Brother and ITV's Grease Is The Word.
He was married to Minnelli from 2002-2003 but they only officially divorced in 2007. He was also known for being a close friend of Michael Jackson.
Gest had been due to tour the country this summer in a musical show called David Gest Is Not Dead But Alive With Soul, a title referring to a misunderstanding in the CBB house.
The soul show will now go ahead in his honour.
Before the service Gaffney said: "David will be sorely missed, there will be a good turn out for him today."
Celebrity Big Brother contestants Jeremy McConnell and Stephanie Davis were also spotted outside the ceremony, alongside Vanessa Feltz and singer Christopher Maloney.
Mourners entered the chapel to Gone Too Soon by Michael Jackson before the coffin was carried in as a seven-piece gospel choir sang Here Comes The Gesty.
Soap star Marsh led the tributes to Gest, describing him as "my very best friend" and saying she had been a fan of his before she met him.
Marsh and Cleo Rocos read out further messages from Dionne Warwick, Petula Clark, Smokey Robinson and Tito Jackson, as well as Gest's sister Barbara Gerber.
A film of Gest talking about his life was also played during the service before Day sang Bring Him Home and the choir sang My Way and Oh Happy Day.
The service concluded with I'll Be There by Michael Jackson and applause from inside the chapel could be heard outside.
A heavy hail storm started as mourners left the service to continue celebrations at a local pub.
Actress June Smith, who met Gest through his close friend Imad Handi, said: "It was every emotion under the sun and it couldn't have been a better tribute to a wonderful, flashy, fun yet still modest man who never blew his own trumpet.
"It was an amazing service for an amazing person. There were lots of tears, of laughter and of sadness.
"I thought David would be looking down saying, 'There is Darren Day singing about me!' I didn't think Darren would be able to hold it together but he did."
Floral tributes from the service were left in the garden of remembrance at the crematorium.
The most eye-catching one was in the shape of a fruit machine complete with handle, with '777 Heaven' and 'Darling David' spelled out in red roses.
The musical note display bore a card saying: "From Liverpool with love."
The Four Seasons Hotel in east London, where Gest was found dead, also sent flowers with a card reading: "From your friends at the Four Seasons Hotel at Canary Wharf. You will be greatly missed. Rest in peace."
It is expected that Gest's ashes will be scattered at a private event in York attended by his closest friends.