María Soledad Alvear Valenzuela (born September 17, 1950), is a Chilean lawyer and former Christian Democrat politician, who was a cabinet member of the Aylwin, Frei and Lagos administrations.

With Ricardo Lagos she worked as campaign manager during the 2000 runoff election, and then under his government she worked as Foreign Minister, signing Free Trade Agreement with the United States, the European Community and South Korea.

On late 2004 Alvear won her party's nomination for the upcoming presidential election, and then was to face the Socialist Party candidate, Michelle Bachelet, in an open primary election, to define a sole Concertación candidate.

However, low support in opinion polls and on her party leadership led her to resign two months before the defining primary.

On 22 September 2022, she officially joined Amarillos por Chile, centrist political party.