Co-Operative Food's poll of 4000 people across 19 cities found Belfast was the second kindest city, with Aberdeen coming in third.
Londoners were the least likely to help a stranger, with Liverpool and Glasgow also at the bottom.
Running after someone to hand them back something they dropped was the most common 'good deed' cited in the survey, followed by giving up a seat on a train or bus for a less able or pregnant passenger.
Helping someone who's lost and taking in post or parcels for a neighbour also regularly featured.
The research also discovered that 18-24 year olds spend the most time helping others.
More than one in ten (12%) said they were sometimes reluctant to help because of fears it would 'look weird', but despite this more than one one in three (35%) said they've been in a situation where they needed help but none arrived.
Matt Doherty has served in churches across Bristol for several years and was born and raised in the city, and told Premier's News Hour: "Actually this is a really great place to be.
"Generally Bristolians are really proud to be so - and for good reason.
"I think it's just doing those small things where the opportunity presents itself.
"These things happen all the time, we don't always notice it, but there's always a choice to do something that's either the bare minimum or to go out of your way and help."
Listen to Premier's Marcus Jones speaking to Matt Doherty on the News Hour:
