People gathered in the market square to mark the exact time a week ago that the Batley and Spen MP was attacked.
Ms Cox was fatally injured outside the village library and tributes to her placed around a nearby statue have grown over the last seven days to form a carpet of thousands of flowers, messages and balloons.
More than 100 people ringed the makeshift memorial for moments of silence, hymns and eulogies led by the vicar of St Peter’s Church, the Reverend Paul Knight.
Rev Knight told the crowd, who held hands around the memorial: “We’re meeting seven days on from the tragedy that hit our community when our MP, Jo Cox, was brutally killed.
“We’re meeting today to remember her, to pray for her family and to pledge ourselves to a better world.
“To pledge ourselves to unity, because that was certainly one of Jo’s passions.”
Thomas Mair, 52, from Birstall, will go on trial in the autumn charged with murdering Mrs Cox, grievous bodily harm, possession of a firearm with intent to commit an indictable offence and possession of a knife.