William Kelly (1840 – 19 September 1907) was an Irish migrant to New Zealand, and became a businessman, soldier and politician.

Kelly was born in 1840 in County Louth, Ireland, and emigrated to New Zealand as a young man in 1863.

The "most sensational electoral contest ever held in the East Coast" electorate was held in January 1876, when mysterious pieces of cardboard were distributed by supporters of George Read in Gisborne, which hotel bars accepted as legal tender.

Read, George Morris and Kelly received 215, 206 and 185 votes, with another candidate coming a distant fourth.

Four candidates were nominated: Kelly; George Morris, who had previously represented the East Coast electorate; George Vesey Stewart, then the owner of the Bay of Plenty Times; and Henry Thomas Rowe, a surveyor and commission agent.