The command will take place on Monday at 5.30 pm at Bangkok's Siriraj Hospital, according to the Secretariat of the House of Representatives.
The premier-to-be Ms Yingluck on Saturday was staying in her home, while an army of reporters awaited outside for updates of her movements.
The House of Representatives on Friday voted 296-3 for Ms Yingluck, a top-party list Pheu Thai MP and sister of ousted premier Thaksin Shinawatra, to become the country's new prime minister. One hundred and ninety-seven votes abstained.
The vote in the 500-seat lower chamber of Parliament came a month after Pheu Thai party won a majority in the July 3 election. It formed a six-party coalition controlling some 300 seats in the 500-seat House.
Upon receiving His Majesty King Bhumibol Adulyadej's royal endorsement, Ms Yingluck will officially assume her duties and be authorised to present a cabinet line-up for royal approval.