William LeBaron Putnam (May 26, 1835 – February 5, 1918) was a lawyer and politician in Maine.
Born in Bath, Maine, Putnam received an Artium Baccalaureus degree from Bowdoin College in 1855, where he was a member of the Peucinian Society.
He worked as a lawyer in private practice in Portland, Maine from 1858 to 1891.
He was a commissioner to negotiate American fishing rights in Canada from 1887 to 1888.
He was confirmed by the United States Senate on March 17, 1892, and received his commission the same day.