The questions are expected to focus on whether Sara Netanyahu used state funds to finance maintenance work and new furniture for the couple's private home in the exclusive coastal city of Caesarea.
Israeli media reported the questioning, and cameras posted outside the police station showed her car arriving. Police declined to comment.
A recent report by the state's official watchdog detailed large sums of public money spent by the couple.
The Netanyahus have long faced scrutiny over their spending and accusations that their lifestyles are out of touch with regular Israelis. Sara Netanyahu in particular has come under fire for her expensive tastes and alleged abusive behavior toward staff.