The ventriloquist, who, with his puppet duck Orville became a staple of Saturday night TV in the 1980s, died last month aged 67.
Mourners gathered at the Sacred Heart Roman Catholic Church in his hometown to pay their respects.
The entertainer's fourth wife Sarah and her children attended the ceremony, alongside Coronation Street star Ken Morley and comedian Jimmy Cricket.
A floral tribute from the Nolan sisters read: "For Keith, a great pro, fantastic talent, [and] a lovely man who will be sorely missed"
Harris entertained generations of children with his sidekick Orville, a bright green duck who wore a nappy and spoke in a high-pitched voice.
He also gave life to the popular puppet Cuddles the monkey, whose catchphrase was 'I Hate That Duck!'.
At the height of his fame, he fronted The Keith Harris Show on BBC One and gave private performances at birthday parties for Prince William and his brother Harry, at the request of Diana, Princess of Wales.
His 1982 single, Orville's Song, was a top five hit, selling more than 400,000 copies.
Harris, who married four times and had three children, was first diagnosed with cancer in 2013 and became ill again in January.
He died in hospital in Blackpool on 28 April.
Friends of Keith Harris have joined his family at his funeral in Blackpool.