Single-pixel imaging (SPI) using a single-pixel detector is an unconventional imaging method that has great application prospects in many fields to realize high-performance imaging. In particular, the recently proposed catadioptric panoramic ghost imaging (CPGI) extends the application potential of SPI to high-performance imaging at a wide field of view (FOV) with recent growing demands. However, the resolution of CPGI is limited by the hardware parameters of the digital micromirror device (DMD), which cannot meet ultrahigh-resolution panoramic imaging needs that require detailed information. Therefore, to overcome the resolution limitation of CPGI, we propose a panoramic SPI based on rotational subdivision (RSPSI). The key of RSPSI is to obtain the entire panoramic scene by the rotation-scanning of a rotating mirror tilted 45°, so that one single pattern that only covers one sub-FOV with a small FOV can complete an uninterrupted modulation on the entire panoramic FOV during a once-through pattern projection. Then, based on temporal resolution subdivision, the image sequence of sub-FOVs subdivided from the entire panoramic FOV can be reconstructed with pixel-level or even subpixel-level horizontal shifting adjacently. Experimental results using a proof-of-concept setup show that the panoramic image can be obtained with 10428 × 543 of 5,662,404 pixels, which is more than 9.6 times higher than the resolution limit of the CPGI using the same DMD. To the best of our knowledge, the proposed RSPSI is the first to achieve a megapixel resolution via SPI, which can provide potential applications in fields requiring imaging with ultrahigh-resolution and wide FOV.