Mary "Mamie" Shields Pyle (February 28, 1866 – December 22, 1949)[1] was a women's suffrage leader in the U.S. state of South Dakota.

Following a failed 1910 referendum on women's suffrage, Pyle became the leader of the South Dakota Universal Franchise League.

Pyle remained president of the South Dakota Universal Franchise League through the state's ratification of the Nineteenth Amendment the following year.

Shields enlisted for the American Civil War as a musician in the 1st New Jersey Volunteer Infantry and served from 1861 until being discharged for disability in 1863.

[5] She continued teaching in Beadle County, South Dakota, until marrying attorney and politician John L. Pyle in 1886.

[7] Pyle was inspired to join the suffrage movement after noticing a local party boss bringing immigrant workers to vote on election day.

[15] With the progress made, Pyle and the League lobbied the legislature to pass another women's suffrage amendment, which would once again be put to a public vote.

[6]: 215  For the public vote, scheduled for November 1916, Pyle changed strategies from using district organizers to mobilizing county leaders to contact every voter in the state.

[6]: 218 In January 1917, Pyle and other suffragettes polled the South Dakota legislature to determine the support for a suffrage amendment.

[6]: 223  Norbeck called a special session of the legislature and asked Pyle to be present to consult on an amendment to the woman's suffrage clause to exclude non-citizens from voting.

Pyle and the Universal Franchise League gave their full support to the amendment and continued to campaign aggressively.

[1][5] The Pyle family home in Huron has been turned into a museum[25] and is listed on the National Register of Historic Places.