Catherine Helen Spence (31 October 1825 – 3 April 1910) was a Scottish-born Australian author, teacher, journalist, politician, leading suffragist, and Georgist.

Her eldest sibling, Agnes, died in infancy, and her sisters were Jessie, Helen, Mary and brothers David, William and John.

[2] Arriving aged 13 aboard Palmyra with her family on 29 October 1839,[5][6] at a time when the colony had experienced several years of drought, the contrast to her native Scotland made her "inclined to go and cut my throat".

[7] He was important in the City holding its elections using an early form of Single transferable voting, inspiring Catherine to later engage in activism in the cause of proportional representation.

Unusually for a woman in those times, Spence learned about production, exchange and wealth in this early developing country, "the value of machinery, of roads and bridges, and of ports for transport and export".

For several years, Spence was the South Australian correspondent for The Argus newspaper writing under her brother's name[2] until the coming of the telegraph.

Spence's second novel Tender and True was published in 1856, and to her delight went through a second and third printing, though she never received a penny more than the initial twenty pounds.

[7] At first treated with scorn by the South Australian government, the scheme was encouraged when the institutions devoted to the handling of troublesome boys became overcrowded.

After reading Henry George's book Progress and Poverty, she brought the issue of finsle tax, taxation of land values only, to the attention of the governments of the three most important Australian colonies in the 1880s.

Spence was an advocate of Thomas Hare's scheme of proportional representation (PR), the single transferable voting (STV) system.

When Spence became vice-president of the Women's Suffrage League, she travelled and lectured both at home and abroad for what she called Effective Voting, also known as proportional representation.

[18][1] During her North American tour, she contributed a comprehensive essay to a seminal book on electoral reform published by Sandford Fleming in Canada.

[19] During her tour she met with prominent electoral reformers in many countries, including Robert Tyson (Canada), Alfred Cridge (U.S.), John H. Humphreys (UK) and Ernest Naville (Switzerland).

In 1911 Preston received a commission to paint a portrait of Spence, now held by the Art Gallery of South Australia, from a citizens' committee of Adelaide.

[26] This portrait was used as the basis of her appearance on the commemorative Centenary of Federation Australian five-dollar note issued in 2001, replacing that of the Queen.

[28] The Catherine Helen Spence Memorial Scholarship was instituted by the South Australian Government in her honour for women aged 20–46.