Bayard Taylor Hainer (1860–1933) was a justice of the Territorial Oklahoma Supreme Court in 1898.

Bayard's family moved to Iowa when the Civil War broke out.

[1] Bayard earned a B. S. from Iowa State College in 1884 (no major identified), and a Bachelor of Laws from University of Michigan in 1887.

Admitted to the bar in Michigan in the same year, he moved to Larned, Kansas to start practicing law.

In that year, the President of the United States appointed him as a justice of the Oklahoma Territory Supreme Court on February 16, 1898, succeeding Judge Bierer.