Lemuel John Bagnall (1844 – 30 April 1917), was a New Zealand businessman and politician who was Mayor of Auckland City from 1910 to 1911.

He became involved in the timber trade and in 1878 purchased a sawmill on the Waihou river with his brothers which they operated till 1912.

Bagnall stood for Parliament for the Auckland Central electorate in the 1905 general election as a conservative candidate, but was defeated by Alfred Kidd.

[4] In 1910 he was elected Mayor of Auckland City, defeating councillor Patrick Nerheny.

His brother, merchant Horatio Nelson Bagnall, was a councillor from 1913 until he died in 1922.