Hundreds of fans lined the streets to pay their respects before watching the funeral livestreamed onto a big screen.
The singer died last month aged 33, surrounded by his family and bandmates – 17 months after being diagnosed with an inoperable brain tumour.
Yesterday, band members Jay McGuiness, Max George, Siva Kaneswaran and Nathan Sykes carried his coffin into St Francis of Assisi church in Petts Wood, south-east London, accompanied by the Oasis hit Champagne Supernova.
Wife Kelsey, 32, who married the star in 2018, gave a moving pre-recorded speech.
She told how they met in a crowded nightclub aged 19 before Parker shot to fame.
Before becoming tearful, she added: “From that moment I told everyone I wanted to marry Tom Parker.”
The congregation erupted into laughter when she added: “Tom told me he was going to be famous and wouldn’t have time for a girlfriend, but he wouldn’t leave me alone.”
She added: “Marrying you was the best day of my life…. Soulmates, that’s what we are. If love could have saved you, you would have lived forever.”
Parker disclosed in October 2020 that he had been diagnosed with stage four glioblastoma and had started radiotherapy.
Despite his diagnosis, in the weeks before his death last month he performed on stage with The Wanted as part of their much-delayed reunion tour.
Celebrities in the aisles included One Direction’s Liam Payne, Olympian Rebecca Adlington, who was at the Parkers’ wedding, and EastEnders actress Louisa Lytton.
Addressing the congregation, 33-year-old Max George said of carrying his friend’s coffin: “I could actually hear him saying, ‘It’s about time’ – as he carried us for the last 12 years.”
The service ended with The Wanted’s hit song Gold Forever, before Kelsey placed a single white rose inside the hearse.