• His best-known discoveries are the enzyme lysozymein 1923 and the antibiotic substance penicillin from the mould Penicillium notatum in 1928
• he shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Florey and Ernst Boris Chain.
• He was made a Knight Grand Cross of the Order of Alfonso X the Wise in 1948.
• In 1999, Time magazine named Fleming one of the 100 Most Important People of the 20th century, stating:
• In 2002, Fleming was named in the BBC's list of the 100 Greatest Britons following a nationwide vote.