Robert Lucas Joiner (November 6, 1841 – May 5, 1920) was a member of the Wisconsin State Senate.
A native of Williamsport, Indiana. Joiner moved to Wyoming, Iowa County, Wisconsin in 1845.[1] He was a farmer and surveyor.[2][3] His father, Lemuel, was also a member of the Senate, as well as the Wisconsin State Assembly.[1] Joiner died in Dodgeville, Wisconsin.[1]