Madam Lee Ai Boon, the wife of Trade and Industry Minister Lim Hng Kiang, died on Saturday.
Madam Lee, 60, had cancer, a statement from the press secretary to Mr Lim said on Sunday.
The wake is held at Singapore Casket and a private funeral will be on Wednesday.
Mr Lim's family has requested that there be no wreaths or collection of bereavement.
They have also asked for all donations to be made directly to Society for the Prevention of Cruelty to Animals and Children's Cancer Foundation.