Ribosomes were discovered in 1955 by Romanian scientist George Palade. Palade first called them dense granules or dense particles by using a electron microscope.

Ribosomes were discovered by George E. Palade in 1955. He also discovered tha ribosomes performed protein synthesis in the cells. In 1974, he was awarded the Nobel Prize. You can find more information here: http://www.nature.com/scitable/definitio...