The names of the victims were read out and candles were lit during the event held outside The Immaculate Heart of Mary Catholic Church in Botwell lane.
Muslims, Christians, Sikhs and others came together with local police officers, councillors and the MP for Hayes and Harlington, John McDonnell.
A silence was also held for people to reflect on the tragedy.
Four people have died after Khalid Masood drove his car along the pavement of Westminster Bridge on Wednesday (March 22) before he stabbed a police officer to death in the grounds of the Palace of Westminster.
Masood was shot and killed by police officers.
The vigil was organised by Hayes in Solidarity and led by Father Paul Smyth.
Children read quotes from well-known figures and a song was performed as an expression of unity.
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