The scientist who discovered cells is Antonie van Leeuwenhoek. He was a Dutch scientist and microscopist who is best known for his discovery of microorganisms and the first person to observe and describe single-celled organisms. He was the first to use a microscope to observe and study cells, and he is credited with discovering bacteria, yeast, and protozoa. He also discovered the structure of the blood vessels, the red and white blood cells, and the cells in the skin. He made his observations using simple microscopes that he made himself, and he was able to magnify objects up to 270 times their original size. His discoveries paved the way for the development of the field of microbiology and the study of cells.