Movement of Socialist Affirmation

{{Infobox political party

| name = Movement of Socialist Affirmation

| native_name = Movimiento de Afirmación Socialista

| colorcode = Red

| leader = Henry Pease
Rolando Ames
Gloria Helfer

| foundation = 1989

| ideology = Christian socialism

| country = Peru

| abbreviation = MAS

| dissolved = 1992

| position = Left-wing

| national = IU (1989-92)
MDI (1992-93)

}}

The Movement of Socialist Affirmation ({{langx|es|Movimiento de Afirmación Socialista}}) (MAS) was a political party in Peru formed in 1989 by left Christian elements of the IU coalition, and active through 1992.{{Cite book |title=Shining and other paths: War and society in Peru, 1980-1995 |date=1998 |publisher=Duke University Press |isbn=9780822322177 |editor-last=Stern |editor-first=Steve J. |pages=287}}{{Cite book |last=Feinstein |first=Tamara |url=https://books.google.com/books?id=UfypEAAAQBAJ&dq=%22Movimiento+de+Afirmación+Socialista%22&pg=PA1981 |title=The Fate of Peruvian Democracy: Political Violence, Human Rights, and the Legal Left |date=2023 |publisher=University of Notre Dame Press |isbn=9780268206215}} Leaders included Henry Pease, Rolando Ames and Gloria Helfer.

MAS worked within IU in the 1989 and 1990 elections. In 1992 it broke with IU, and was one of the organizations founding MDI. MAS worked with MDI in the 1992 and 1993 elections. In the 1993 referendum, it supported the No.{{Citation needed|date=June 2024}}{{Inconsistent}}

MAS was represented in President Alberto Fujimori's first cabinet by Gloria Helfer, who was appointed Minister of Education.{{Cite book |last=Poole |first=Deborah |title=Peru: Time of Fear |publisher=Latin American Bureau |isbn=090615670X |location=London |pages=149}}