MacNally, Leonard, 1752–1820, Irish political informer. A lawyer, he joined the United Irishmen and defended many of their members in court. His clients, however, were invariably convicted, and after his death it was discovered that MacNally had been in the pay of the British government. It was he who betrayed Lord Edward Fitzgerald (1798) and Robert Emmet (1803). MacNally wrote many plays and the song "The Lass of Richmond Hill."