The Election Commission sought court approval to postpone the vote, arguing the country was too unsettled by mass anti-government protests in the capital, now in their third month, to hold a successful vote.
Ms Yingluck called the election in the hope of confirming her hold on power in the face of protests trying to force her from office.
Thitinan Pongsudhirak, political analyst at Chulalongkorn University in Bangkok, said: "The ruling is likely to be seen as part of the build-up to dislodge Yingluck from office, similar to what happened in 2008 but with higher stakes and higher potential for violence and unpredictability."
In 2008, courts brought down two governments allied to Ms Yingluck's brother and ex-premier Thaksin Shinawatra, who now lives in self-imposed exile.
The ruling appears to fudge a decision. It gave the Election Commission the right to postpone the election planned for a week tomorrow but also ruled the commission would have to agree on a new date with the government.
Varathep Rattankorn, a minister at the prime minister's office, said it would study the ruling.