Martha Lena Morrow Lewis (1868–1950) was an American orator, political organizer, journalist, and newspaper editor.

An activist in the prohibition, women's suffrage, and socialist movements, Lewis is best remembered as a top female leader of the Socialist Party of America during that organization's heyday in the first two decades of the 20th century and as the first woman to serve on that organization's governing National Executive Committee.

Martha Lena Morrow was born in December 1868 in rural Warren County, Illinois where she was raised.

For her first involvement, Morrow took a post as a national lecturer for the Women's Christian Temperance Union (WCTU), remaining in that position until 1898.

"[5] Morrow joined the Socialist Party of America (SPA) in 1902 and redirected her activism from women's suffrage to socialism.

[2] Lena Morrow Lewis was indefatigable in promoting the Socialist Party as a national organizer and lecturer from 1908 to 1914.

[2] Lewis was later tapped for the American delegation to the 1910 International Socialist Congress in Copenhagen, Denmark.

[10] Middle-aged and divorced, Lewis was in the power structure of the Socialist Party and stood as one of its "outstanding lecturers and organizers".

[12] In 1931, Lewis was elected to the governing National Executive Committee of the Socialist Party of America.

[12] Lewis resigned from the Socialist Party in 1936 to join the Social Democratic Federation (United States) which separated from the SPA over ideological disagreements.

[19] The Morrow collection consists of two linear feet of material in five archival boxes and has been microfilmed by the library for the use of scholars.