The conference is being held by the Santa Marta Group and organised by the Bishops' Conference of England and Wales.
It comes after a two-day meeting earlier this year in Rome when Pope Francis said trafficking was "an open wound on the body of contemporary society; a crime against humanity".
Cardinal Vincent Nichols, Archbishop of Westminster, and Met Police Commissioner Sir Bernard Hogan-Howe have invited Home Office officials to discuss how to keep the welfare of the trafficked victim at the heart of all law enforcement.
Home Secretary Theresa May and the Minister for Modern Slavery and Organised Crime Karen Bradley will both address the conference.
Mrs May, a Christian, said: "I am delighted to be hosting the Santa Marta Conference, a forum dedicated to the eradication of modern slavery which brings together police chiefs and bishops from across the globe.
"This government has taken great strides to tackle this abhorrent crime."
Cardinal Nichols said: "The Santa Marta Group is not about theory, it is focused on rescuing people who have become victims of trafficking and find themselves in an impossible situation."
Sir Bernard Hogan-Howe said: "Knowing the full scale of the problem is an almost impossible task as those most vulnerable to exploitation often live at the margins of our society and the criminals hide in the shadows.
"However, this must not stop those who can help, from all nations, making the commitment to do everything they can to enable trafficking victims to escape the clutches of their captors and bring the criminals involved to justice.
"We know our collective efforts are not adequate to end this modern form of slavery and therefore we must all do more."