The former BBC Breakfast presenter died on August 31 at the age of 66 after a “challenging and committed fight against prostate cancer”, which was diagnosed in November 2017.
Family and close friends, including his BBC Breakfast co-hosts, attended a private ceremony at Holy Trinity church in Blythburgh, Suffolk, on Friday afternoon.
Williams, who anchored 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.
“I wish he were able to understand how much he was valued, and I think it is incredible the number of people here who just wanted to come and celebrate and pay their respects to him.
“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.”
Williams, who arrived dressed in black alongside broadcaster Reid, said she will remember Turnbull “with a smile”.
Turnbull joined BBC Breakfast in 2001 as a presenter alongside Williams and they worked together until 2012 when she left after the programme moved from London to Salford.
The presenter co-anchored alongside Reid until 2014 when she left the show to join ITV, and he was then joined by Louise Minchin and others.
Turnbull signed off from the sofa in 2016 after 15 years.
Minchin also attended the funeral along with other famous names including Martha Kearney, Mike Bushell, Charlotte Hawkins and Nick Robinson.
BBC presenter and friend, Robinson told PA he is “going to miss him terribly.”
“People sometimes say people who present TV shows get paid a vast amount of money, they get a lot of praise and it’s easy. And it is easy, but the funny thing is hardly anybody can do it well.
“Bill Turnbull did it brilliantly because he was a seriously good journalist but he also was a human being who could reach out, empathise and be warm with people, from presidents, kings and queens down to people talking about their pets.
“People may say that’s easy, but funnily enough I do not know anybody else as good as Bill Turnbull at doing it,” he said.
Munchetty, who shared BBC Breakfast’s red sofa with Turnbull for several years, told PA: “Bill was the grammar hammer – he was so on top of his grammar plurals, singulars… He was all over it.
“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.
“To sit next to Bill was always an experience, it was always fun, it was always focused, but it was also about the audience.
“It was telling the story, being part of the story, which is always a privilege, and hearing people’s experiences and helping to relay those to our audience.
“It was the audience – that’s what Bill was about.”
The presenter said she will remember Turnbull as a “funny, charming, cheeky guy”.
Turnbull’s two sons and son-in-law were among the six pallbearers carrying his oak coffin, which was adorned with a red rose and a purple bouquet, into the church.
The broadcaster had been an avid supporter of Wycombe Wanderers during his life, and the club’s manager, Gareth Ainsworth, attended the funeral wearing black sunglasses.
A signed Wycombe Wanderers shirt with the number 60 had been placed on a bench outside the church as mourners filed in to celebrate the life of the veteran journalist.
Turnbull started his broadcasting career at Scotland’s Radio Clyde in 1978, joining the BBC as a reporter for Radio 4’s Today programme in 1986 before becoming a reporter for BBC’s Breakfast Time two years later.
David Kogan, who was Turnbull’s former editor in 1984, told PA: “The thing about Bill was, what you saw on screen was what he was very much like as an individual.
“He was incredibly funny, incredibly smart, had a very deep appreciation both for people and also the things around him.
“As a friend he was a very funny companion with whom I went on long trips, we listened to music, we went to football, he was a man who had great depth of personality and character, great depth of friendship and family. He was a great guy.
“I’ve witnessed Bill for the last five years fighting this illness with incredible strength of will, and his family also fighting it with their incredible levels of support, and in the last few weeks of his life, when the battle was clearly being lost, he was a man who was not going to give up life easily.
“It was a tragic moment when we lost him, we lost him far too young, it is a very emotional day and we will miss him.”
Kogan added that Turnbull was not only a friend but “as close to me as a brother could be”.
In 1990, Turnbull became a correspondent for BBC News and reported from more than 30 countries, covering notable stories including the Monica Lewinsky scandal and the OJ Simpson trial in the US.
After moving back to the UK, he became one of the main presenters on BBC News 24, as it was then called.
Turnbull also worked for BBC Radio 5 Live, including presenting Weekend Breakfast.
He was diagnosed with prostate cancer in November 2017 and later fronted the Channel 4 documentary Bill Turnbull: Staying Alive.
Other notable TV appearances included BBC One’s Songs Of Praise and Strictly Come Dancing.
In 2016, he joined Classic FM, where he hosted programmes on Saturdays and Sundays, and also launched and presented Classic FM’s Pet Classics, to help keep pets and their owners relaxed during fireworks season.
Turnbull had a passion for beekeeping, leading to the 2011 publication of his book The Bad Beekeepers Club, a humorous account of the ups and downs of an apiarist.