Arthur John Lobb (July 26, 1871—July 4, 1928) was a politician in Manitoba, Canada. He served in the Legislative Assembly of Manitoba from 1915 to 1920, as a member of the Liberal Party.^[1]

Lobb was born in Cornwall, United Kingdom, the son of John Lobb, and was educated at English public schools. He moved to Canada in 1894, and worked as a general merchant and grain and lumber dealer. In religion, he was a Methodist. Lobb married Elizabeth Geddes in 1907.^[2]

He first ran for the Manitoba legislature in the 1914 provincial election, and lost to Conservative Isaac Riley by fifty-nine votes in the constituency of Rockwood. He ran again in the 1915 election, and defeated^[1] Conservative candidate Thomas Scott by 636 votes. The Liberals won this election, and Lobb served as a backbench supporter of Tobias Norris's administration for the next five years.

He ran for re-election in the 1920 provincial election, but lost to Farmer candidate William McKinnell^[1] by a single vote. He attempted to return to the legislature in the 1927 election,^[1] but placed third against McKinnell.

He died at home in Winnipeg at the age of 56.^[2]