Ni una menos (Spanish: [ni ˈuna ˈmenos]; Spanish for "Not one [woman] less") is a Latin American fourth-wave grassroots feminist movement, which started in Argentina and has spread across several Latin American countries, that campaigns against gender-based violence. In its official website, Ni una menos defines itself as a "collective scream against machista violence." The campaign was started by a collective of Argentine female artists, journalists and academics, and has grown into "a continental alliance of feminist forces". The movement regularly holds protests against femicides, but has also touched on topics such as gender roles, sexual harassment, gender pay gap, sexual objectification, legality of abortion, sex workers' rights and transgender rights.
The movement became nationally recognized with the use of the hashtag #NiUnaMenos on social media, title under which massive demonstrations were held on June 3, 2015, having the Palace of the Argentine National Congress as a main meeting point. The protest was organized after the murder of 14-year-old Chiara Paez, found buried underneath her boyfriend's house on May 11, because she wanted to keep the baby and he did not, so he beat her to death when she was a few weeks pregnant. A viral phenomenon which extended to countries such as Uruguay and Chile, it managed to congregate around 200,000 people in Buenos Aires alone. On June 3, 2016 the multitudinous demonstration took place once again throughout Argentina's most important cities, under the new slogan #VivasNosQueremos (English: #WeWantUsAlive); the march was also replicated in Montevideo, Uruguay and Santiago, Chile. A #NiUnaMenos march also took place in Lima, Peru on August 13, 2016, with thousands of people gathering in front of the Palace of Justice. Newspaper La República considered it the largest demonstration in Peruvian history.
On October 19, 2016 the Ni una menos collective organized a first-ever women mass strike in Argentina, in response to the murder of 16-year-old Lucía Pérez, who was raped and impaled in the coastal city of Mar del Plata. It consisted of a one-hour pause from work and study early in the afternoon, with protesters dressed in mourning for what was known as Miércoles negro (Spanish for "Black Wednesday"). These protests became region-wide and gave the movement a greater international momentum, with street demonstrations also taking place in Chile, Peru, Bolivia, Paraguay, Uruguay, El Salvador, Guatemala, Mexico and Spain. A week later, a protest also took place in Rio de Janeiro, Brazil, which has been considered "yet another clear sign that Ni una menos has become a rallying cry for the region." On March 8, 2017, Ni una menos took part of the International Women's Strike. The strike was spearheaded in the United States by the leaders of the Women's March on Washington, who in a call to arms letter in The Guardian pointed to Ni una menos as an inspiration.
Since the first #NiUnaMenos in 2015, demonstrations take place every year in Argentina on June 3.
In 2016, Argentine scientists Julián Petrulevičius and Pedro Gutiérrez named Tupacsala niunamenos, a dragonfly species found in La Rioja, after the movement. The genus Tupacsala was chosen in honor of Túpac Amaru II and Milagro Sala's organization named after him.
The collective takes its name from a 1995 phrase by Mexican poet and activist Susana Chávez, "Ni una muerta más" (Spanish for "Not one more [woman] dead"), in protest to the female homicides in Ciudad Juárez. Chávez herself was assassinated in 2011, moment in which the phrase became a "symbol of struggle". The first protest organized by Ni una menos was held in Recoleta, Buenos Aires on March 26, 2015, and consisted of a reading marathon, performance art and screenings; the catalyst of the event was the murder of Daiana García, found dead in a garbage bag on March 16.
- 2020 legalization of abortion in Argentina: First-trimester elective abortion in Argentina was legalized on 30 December 2020. Half a decade of protests by Ni una menos were credited as pivotal advocacy for the change in law. 
- Creation of the Registry of Femicides
- Creation of the Centre for the Registration, Systematisation, and Monitoring of Femicides
- Created to keep a record of the number of cases of gender-based violence
- 2017 Women's March
- Ele Não movement (Brazil, 2018)
- Feminism in Latin America
- Feminism in Argentina
- Feminism in Chile
- Feminism in Mexico
- Women in Argentina
- Women in Chile
- Women in Paraguay
- Women in Peru
- Women in Uruguay
- Gender inequality in Bolivia
- LGBT rights in Argentina
- List of protests in the 21st century
- Roffo, Julieta (29 May 2015). "Un estallido de imágenes para decir #NiUnaMenos". Clarín (in Spanish). Clarín Group. Retrieved 25 April 2017.
- Roffo, Julieta (9 April 2017). "El emotivo homenaje de Liniers a Micaela" (in Spanish). Infobae. Retrieved 25 April 2017.
- Young, Linda (11 December 2017). "A Women's Strike Organizer on Feminism for the 99 Percent". Broadly. Vice Media. Retrieved 5 May 2018.
- Branigan, Claire; Palmeiro, Cecilia (8 March 2018). "Women Strike in Latin America and Beyond". North American Congress on Latin America. Retrieved 4 October 2021.
- Palmer, Rose (15 December 2017). "Ni Una Menos: An Uprising of Women in Argentina". Culture Trip. Retrieved 5 May 2018.
- "Qué es Ni una menos" (in Spanish). Ni una menos. Retrieved 21 April 2017.
- Gago, Verónica; Santomaso, Agustina (7 March 2017). "Argentina's Life-or-Death Women's Movement". Jacobin. Bhaskar Sunkara. Retrieved 25 April 2017.
- Pomeraniec, Hinde (8 June 2015). "How Argentina rose up against the murder of women". theguardian.com. Retrieved 22 April 2017.
- "En Uruguay, Chile y México también: ¡Ni una menos!" (in Spanish). La Izquierda Diario. 4 June 2015. Retrieved 22 April 2017.
- Porter, Tom (4 June 2015). "Argentina: 200,000 rally against femicide and domestic violence in Buenos Aires". International Business Times. IBT Media. Retrieved 22 April 2017.
- "Multitudinaria marcha en Buenos Aires contra la violencia machista". El Periódico de Catalunya (in Spanish). Grupo Zeta. 4 June 2016. Retrieved 24 April 2017.
- Rodríguez, Fernando (3 June 2016). "NiUnaMenos: 275 femicidios entre una marcha y otra". La Nación (in Spanish). SA La Nación. Retrieved 24 April 2017.
- "Uruguay: Miles de personas marchan contra la violencia hacia las mujeres". CrónicaViva (in Spanish). Universidad Jaime Bausate y Meza. 4 June 2016. Retrieved 24 April 2017.
- "Marchan en Argentina, Chile y Uruguay contra feminicidios" (in Spanish). Periódico Vanguardia. 3 June 2016. Retrieved 25 April 2017.
- "#NiUnaMenos: así fue la marcha contra la violencia a la mujer". El Comercio (in Spanish). Grupo El Comercio. 14 August 2016. Retrieved 25 April 2017.
- Chinchay, Maricarmen; Cortijo, Carlos (14 August 2016). "La más grande de la historia". La República (in Spanish). Grupo La República. Retrieved 25 April 2017.
- Schinca, Ximena (19 October 2016). "Women set for first-ever general strike in Argentine history". Buenos Aires Herald. Editorial Amfin S.A. Retrieved 25 April 2017.
- Pardo, Daniel (14 October 2016). "El "aberrante" caso del empalamiento de una niña de 16 años que indigna a Argentina" (in Spanish). BBC Mundo. BBC World Service. Retrieved 25 April 2017.
- "Women Across Latin America Protest After The Rape And Murder Of A Teenage Girl". HuffPost. AOL. 20 October 2016. Retrieved 25 April 2017.
- Gordon, Sarah (21 October 2016). "NiUnaMenos: How the brutal gang rape and murder of a schoolgirl united the furious women of Latin America". telegraph.co.uk. Retrieved 25 April 2017.
- "#NiUnaMenos: Varios países se suman al clamor de Argentina". El Comercio (in Spanish). Grupo El Comercio. 19 October 2016. Retrieved 25 April 2017.
- Goñi, Uki (20 October 2016). "Argentina's women joined across South America in marches against violence". theguardian.com. Retrieved 22 April 2017.
- Jensen, Emily (26 October 2016). "Ni Una Menos Reaches Rio: Is There Hope To End Gender Violence In Brazil?". The Bubble. Archived from the original on 15 April 2018. Retrieved 22 April 2017.
- Beatley, Megan (9 March 2017). "Meet the Argentine Women Behind Ni Una Menos, the Feminist Collective Angela Davis Cites as Inspiration". Remezcla. Remezcla LLC. Retrieved 25 April 2017.
- Alcoff, Linda Martín; Arruzza, Cinzia; Bhattacharya, Tithi; Fraser, Nancy; Ransby, Barbara; Taylor, Keeanga-Yamahtta; Odeh, Rasmea; Davis, Angela (6 February 2017). "Women of America: we're going on strike. Join us so Trump will see our power". theguardian.com. Retrieved 25 April 2017.
- "Argentinala Cristinae: dos científicos del Conicet bautizaron a un insecto "en honor" a Cristina Kirchner". La Nación (in Spanish). SA La Nación. 14 April 2017. Retrieved 24 April 2017.
- "#NiUnaMenos: ¿Quién fue la autora de la consigna que une a miles contra la violencia de género?" (in Spanish). Minutouno.com. 3 June 2015. Retrieved 26 March 2018.
- Subirana Abanto, Katherine (4 March 2018). "El tiempo de la acción". El Comercio (in Spanish). Retrieved 26 March 2018.
- "Maratón de lectura contra los femicidios" (in Spanish). Sur Capitalino. 26 March 2015. Retrieved 22 April 2017.
- Goñi, Uki; Phillips, Tom (30 December 2020). "Argentina legalises abortion in landmark moment for women's rights: Country becomes only the third in South America to permit elective abortions". Abortion. The Guardian. Archived from the original on 30 December 2020. Retrieved 30 December 2020.
- Politi, Daniel; Londoño, Ernesto (30 December 2020). "Argentina Legalizes Abortion, a Milestone in a Conservative Region:The Senate vote on Wednesday was a major victory for Latin America's growing feminist movement, and its ripple effects are likely to be widespread". Americas. The New York Times. Retrieved 30 December 2020.
- "OM - CSJN". www.csjn.gov.ar. Retrieved 26 November 2021.
- "La politización de Ni Una Menos: áspero debate en Intratables. Mirá el video". El Intransigente (in Spanish). Infobae. 5 June 2017. Archived from the original on 12 October 2017. Retrieved 25 June 2017.