William Blue (c. 1767 – 7 May 1834) was an Australian convict who, after completing his sentence, became a boatman providing one of the first services to take people across Sydney Harbour.

Although Billy Blue's place and date of birth are uncertain, convict records suggest he was born in Jamaica, New York, around 1740 or 1767.

[3] On 4 October 1796, Blue was convicted, at Maidstone, in Kent, of stealing raw sugar and sentenced to seven years' transportation.

[5] Governor Macquarie named him "The Old Commodore" and he ran his ferry dressed in a blue naval officers coat and top hat.

[2] It was said that Blue's law infringements were frequent, but due to his colourful personality, they were looked upon with a "benevolent air" by the authorities.