This paper presents a dedicated multi-size hardware design for the Discrete Cosine Transform type II (DCT-II) of AV1 encoder. The DCT-II is one of four transform kernels supported by AV1; however, DCT-II is used in all configurations defined by AV1. Moreover, the 1D DCT-II can be applied for five different sizes ranging from 4-points up to 64-points. The 1D multi-size DCT-II was designed to process multiple transform sizes in parallel, always processing 64 samples in parallel for any size. The presented solution can process UHD 8K videos at 60 frames per second when running at 46.3 MHz, with a power dissipation of 44.48 mW and an area of 261.28 Kgates. To the best of authors’ knowledge, this is the first work in the literature presenting a hardware design for the AV1 DCT-II transform.