Frank Bird Linderman (September 25, 1869 – May 12, 1938) was a Montana writer, politician, Native American ally and ethnographer. Born in Cleveland, Ohio, he went West as a young man and became enamored of life on the Montana frontier. While working as a trapper for several years, he lived with the Salish and Blackfeet tribes, learning their cultures. He later became an advocate for them and for other northern Plains Indians. He wrote about their cultures and worked to help them survive pressure from European Americans. For instance, he supported establishment of the Rocky Boy Indian Reservation in 1916 in Montana for landless Ojibwe (Chippewa) and Cree, and continued as an advocate for Native Americans to his death.

Linderman worked at various jobs throughout his life: as a fur trapper, then an assayer, and later an agent for Guardian Insurance of America. He owned a hotel for two years. For another two years, he published a newspaper, the Sheridan Chinook. He served two terms in the Montana Legislature and campaigned for a seat in Congress. He published his first collection of Native American tribal stories in 1915 and wrote twenty more books over the next two decades. He wrote to share what he knew about Native American cultures and to preserve their traditional stories. His friend Charles Marion Russell, noted painter, illustrated many of these books.

Linderman was born in Cleveland, Ohio. He was the child of James Bird Linderman and Mary Ann Brannan Linderman. He attended schools in Ohio and Illinois, including Oberlin College. In 1885, at the age of sixteen, he moved to the Swan Valley of Montana Territory in search of "the most unspoiled wilderness I could discover."

While working as a trapper from 1885 to 1891, Linderman met many members of the Bitterroot Salish (also known as Flathead) and Kutenai tribes. He set up camp on their territory on the shores of Flathead Lake, where he learned their ways and lived as they did. To know them better and communicated for trading, he mastered Plains Indian sign language, and he became known by the Crow as "Sign-talker", or, sometimes Great Sign-talker. The Blackfeet called him Iron Tooth, the Kootenai knew him as Bird-Singer, and the Cree and Chippewa called him Glasses or Sings-like-a-bird.

In 1891 he met his future wife, Minnie Jane Johns, in Demersville (now Kalispell). He knew he needed steady work in order to marry, and in 1892 he left his trapping career and started working as a watchman at the Curlew Mine in Ravalli County. Stearne Blake, part owner of the mine, asked him to take over bookkeeping and to assay silver and lead ore. Linderman promptly ordered books and taught himself to do these jobs. He and Minnie married in Missoula in 1893.

After the Curlew Mine closed, Linderman moved with his family in 1893 to Butte where he worked as chief assayer and chemist for the Butte & Boston Smelter. Two daughters were born to the Lindermans while they lived in Butte. He complained about the brutality of the city, saying that it was overrun with rough immigrants from Europe. He worked there until 1897, moving in 1898 to Brandon, Montana, where their third daughter was born. His parents joined him in Montana the following year.

Around 1900, the Linderman family moved to Sheridan, Montana, where Frank worked several jobs, as an assayer, furniture salesman, and newspaperman. He bought the local newspaper and renamed it the Sheridan Chinook. He bought most of the paper's content from a publishing house in Spokane, but each week he published a few columns of his own writing—poetry, "Uncle Billy" sayings, and stories about local miners.

Linderman became active in politics and was elected in 1902 to the Montana Legislature as the representative from Madison County, Montana; his term was one year, and he was elected again in 1904, serving in 1905. That same year, the Linderman family moved to the capital city of Helena. After his term in the legislature, Linderman served as assistant secretary of state from 1905 to 1907. He also opened an assay office in Helena.