Hundreds of people packed into the parish church in Birstall to remember their local MP in a service mainly of silence punctuated by readings, music and prayers.
Friends, colleagues and people who said they had never even met Ms Cox crammed into every pew in St Peter's Church, with others standing in all other available spaces.
Among those who came together to remember the young MP were many of her Labour colleagues, including Yvette Cooper, Dan Jarvis, Rachel Reeves and Caroline Flint.
Speaking after a service in memory of her colleague, Wakefield MP Mary Creagh described Ms Cox as "a woman whose wisdom and wit and integrity shone through in everything she did, who packed more into her short life than most of us will achieve in our longer lives."
The Bishop of Huddersfield, the Rt Rev Dr Jonathan Gibbs, told the packed congregation:
He said he knew two things about Ms Cox. The first was that she was "a woman who was utterly committed to serving others".
The other, he said, was that she was "someone who was deeply committed to her own family as a wife and a mother".
The bishop said: "Tonight we honour both of those."