Thousands lined the route of the procession as it made its way to the park from Hanwell Community Centre. Some 350 people, half of them children, took part.
The theme was music and the colourful parade even featured a replica of the Hanwell Community Centre, where The Who, Uriah Heep, Deep Purple and Led Zeppelin used to rock and rehearse.
Live music kept feet tapping throughout the day, while the pony rides, crocodiles and petting farm kept children entertained.
There was an array of stalls selling food and crafts, and also a dog show, funfair, and sports zone with QPR. The community arena featured local groups showcasing their skills, such as kabaddi and Polish dancing.
Hanwell resident Jon Clowes said: “It is the best yet. There are more stalls and more things for the children. We’ve had a great day.”
His six-year-old son Archie said he particularly liked the bouncy castle, while his daughter Molly, two, loved the animal zone.
Rachel Miller went with her husband and two-year-old daughter. “It’s lovely to see the whole community coming together, talking together and having fun.”
Elaine Buchanan, from Perivale, said: “There are plenty of things for children and adults to do. There are lots of charity stalls with information.”
Carnival chairman Alastair Mitton said: “We are delighted that an estimated 30,000 people turned up for one of the best carnivals in years. Our charities have all said it exceeded their expectations.
“Hanwell Carnival is an entirely community-organised event and this proves what a strong community there is. What an amazing day, what an amazing place Hanwell is.”
Hanwell Carnival is London's oldest, first taking place in 1898, and was established to raise money for the Cottage Hospital (now Ealing Hospital).