Seventeen people have been confirmed dead but that number is expected to rise.
Searches are continuing for bodies inside the building, while a criminal inquiry's underway.
Organised by St John's Notting Hill and the British Pakistani Christian Association, the short interfaith service at sundown will include an Urdu Bible recital, Arabic poem recital and a parishioner's lament.
Speaking to Premier, Rev Dr William Taylor, Police Chaplain for the Royal Borough of Kensington & Chelsea and Vicar of St John's Church, said: "We are aware of the grief, loss and pain of those affected.
"This has touched some raw nerves in the community's heart and we feel strongly that we need to offer a space for the community to come and grieve together."
Wilson Chowdhry from the BPCA said: "The size and scale of the human tragedy left me feeling obliged to help and I have been involved in the local disaster recovery programme since the first day.
"Conversations with survivors and members of the local community indicated a universal desire to remember the victims and share communal grief."
People are encouraged to bring candles and flowers to St John's Church on Lansdown Crescent, Notting Hill. The service begins at 9.30pm.
Listen to Rev Dr William Taylor speaking with Premier's Marcus Jones: