Rafflesia speciosa is a parasitic plant species of the genus Rafflesia. It is endemic to the Philippine islands of Panay and Negros.

R. speciosa was discovered as late as 2002 in the mountains of Sibalom Natural Park in Antique, Panay by members of an outdoor club. It was adopted as the symbol of Sibalom Natural Park and the municipality of Sibalom.

Rafflesia is a genus of parasitic flowering plants. It contains approximately 27 species, all found in southeastern Asia, on the Malay Peninsula, Borneo, Sumatra, and the Philippines. The plant has no stems, leaves or true roots. It is an endoparasite of vines in the genus Tetrastigma, spreading its absorptive organ, the haustorium, inside the tissue of the vine. The only part of the plant that can be seen outside the host vine is the five-petaled flower. In some species, such as Rafflesia arnoldii, the flower may be over 100 centimetres in diameter, and weigh up to 10 kilograms.

The flowers look and smell like rotting flesh, hence its local names which translate to "corpse flower" or "meat flower". The vile smell that the flower gives off attracts insects such as flies, which transport pollen from male to female flowers.