María Conchita Alonso was born María Concepción Alonso Bustillo in Cienfuegos, Cuba, the daughter of Ricardo Alonso and María Conchita Bustillo. Her family moved to Venezuela when she was five years old, in 1962, after the Cuban Revolution. She had her first experience in show business when she was crowned Miss Teenager of the World in 1971, and was Miss World/Venezuela in 1975 where she became sixth runner-up in the Miss World pageant won by Puerto Rico's Wilnelia Merced; she quickly became a top model and a popular singer/actress in Venezuela.
Alonso's first gold album and number one song in the charts was "Love Maniac" in 1979, her name as a singer back then was A'mbar, after that followed her second number 1 with "The Witch" and soon after "Dangerous Rhythm". In what is generally considered to be her best known song, she was asked by Giorgio Moroder to write the lyrics in Spanish and sing "Vamos a Bailar" which he had written to be part of the soundtrack for the film Scarface. The song instantly became a classic amongst Spanish speakers despite failing to garner any major attention outside of Cuba where it was recorded. As her two albums with Ambar and her solo debut were recorded in English, it was her second album "Maria Conchita" from 1984 that made her a singing star in the Spanish-speaking market, receiving a "Best Latin Artist" Grammy nomination for it in 1985.
Alonso issued an "Open Letter to Sean Penn" online on March 29, 2010 regarding his support of then-President Hugo Chávez. She used a point-by-point refrain of "WHY" in her letter questioning various issues occurring in Venezuela. In December 2011, she got into a heated exchange with Penn at a Los Angeles airport during which Penn called her a pig and she responded by calling Penn a communist.
In an August 2012 Spreecast interview, Alonso stated her opposition to the reelection of President Obama, saying that if reelected he will take steps to make the United States become more like Venezuela under the Chávez government.
In the fall of 2008, Alonso endorsed the presidential campaign of Republican nominee John McCain, writing:
As a Latina and a new American citizen, I believe in this country and its people, and I believe that we need more than just "change." We need a leader who can bring about the right kind of change, and John McCain has the experience and judgment necessary to lead us in these uncertain times. I grew up in Cuba and Venezuela, and I am appalled that Barack Obama apparently wants to emulate the "spread the wealth" economic policies of those countries and negotiate with their leaders.
—Maria Conchita Alonso
In January 2014, Alonso resigned from a San Francisco production of The Vagina Monologues after appearing in an advertisement for Republican candidate for Governor Tim Donnelly.
In September, 17 2014, Venezuelan President Nicolás Maduro asked Interior Minister Miguel Rodriguez Torres to pursue on court legal actions to strip Alonso of her Venezuelan citizenship.  The reason was her public request on a radio interview for a military intervention against Venezuela: "In my opinion, (the US) must intervene, because the Cubans already invaded without firing a single bullet because they gave it (Venezuela) for free. So I would like that the US would invade using bullets to get all those communist out of Venezuela" 
^ ab"All those people are Chavistas, all those people are controlled by Chavez... So they say what Chavez wants them to say... No, he was not elected democratically. The first time he was elected democratically, but the last two time[s], the referendum and this last month of December, he was not." Hannity & Colmes, Fox News. June 2007.
^Geraghty, James. "After Watching Her Speak, Giuliani Was an Afterthought," National Review Online. May 1, 2007.