BBC broadcasters including Sian Williams, Susanna Reid, Charlie Stayt and Naga Munchetty were among those who celebrated his life at a private ceremony at Holy Trinity church in Blythburgh, Suffolk, on Friday (16 September).
Martha Kearney, Mike Bushell, Louise Minchin, Charlotte Hawkins and Nick Robinson were also among the mourners.
Williams – who presented BBC Breakfast with Turnbull for more than a decade - told the PA news agency: “I think it is a day of sadness and reflection, and I hope sometime today there will also be time to celebrate his life because he was a great friend and a great man.
“And he has so many different connections to so many different people who cherish him that I hope we can have that time together where we can share those memories."
The TV star said she wished Turnbull knew "how much he was valued".
"I think it is incredible the number of people here who just wanted to come and celebrate and pay their respects to him," she went on.
“Bill made a lot of friends and he was a very loyal friend and he was great to work with as a professional, but when you’re sitting alongside someone like that there is a lot of trust that goes with that.
“I think the reason that so many people have turned out today to pay their respects – to think about him and share memories of him and to celebrate him – is because he was a good man.
“He was a great bloke, he was great to work with, he was a great friend and you see that here with the number of people who wanted to express that.”
Munchetty, who shared the red sofa with Turnbull for several years, said she would remember the TV star as a “funny, charming, cheeky guy”.
“Bill was the grammar hammer; he was so on top of his grammar plurals, singulars… He was all over it,” she said.
“He was passionate about the job and passionate about the journalism and passionate about the audience. The audience was all that mattered and all that does matter and Bill never forgot that – he was a joy to sit beside."
Munchetty said it was "always fun" sharing the sofa with Turnbull and that he was all about the audience.
Turnbull was on BBC Breakfast from 2001 to 2016 and was a favourite with viewers.
He was diagnosed with cancer in 2017 and went public with his diagnosis in 2018.
Additional reporting from PA.
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