The historic items were taken during a break-in to Abercorn Church in Abercorn near South Queensferry.
The bibles are thought to be up to 200 years old and were lent to the church by the Hopetoun family, who own the Hopetoun House stately home and 6,500 acre estate in West Lothian.
The books are about two foot by one foot in size and are around five inches thick. Each is bound with red leather and has distinctive brass plating on the corners.
Constable Andrew Young said: "Both bibles hold considerable value not only in monetary terms but also have historic significance for the local community.
"We are extremely keen to recover these items and return them to the church as quickly as possible."
Lord Hopetoun, speaking on behalf of the Hope family, added: "We are very distressed at the theft of these bibles. They have been on loan from my family to Abercorn Kirk for a long time and recently, the Kirk Session of which I am part had reluctantly to take the decision to lock the church after a series of antisocial incidents.
"To be confronted now with the theft of these irreplaceable pulpit bibles is deeply sad.
"If anyone has any knowledge of their whereabouts, I would urge them to contact the police as they are of huge value to the Abercorn community."
The bibles were stolen between midday on Sunday July 17 and 2pm on Saturday July 23.
