Liliana Alonso (born 18 May 1954) (née Negre) is an Argentine Justicialist Party (PJ) politician.

She had a career in the judicial system and at the state prosecutor's office of San Luis, and is a prolific writer.

She is close to her fellow San Luis senator Adolfo Rodríguez Saá, opposing the kirchneristas (followers of Néstor Kirchner) of the Front for Victory.

They have formed an alliance with other Peronists from the provinces (Peronismo Federal) opposed to the centralization and authoritarian style of the Kirchners and represents them as the second vice-president of the Senate since February 2008.

Negre de Alonso is a devout Roman Catholic and a member of Opus Dei.