Her family left Colombia when she was five years old, and lived in Peru and Mexico City before moving to Houston, Texas when she was 15.

[6][7][8][9] Upon graduation from Stanford, Hidalgo received the Omidyar Network Postgraduate Fellowship to work with an international organization.

[10] She moved to Thailand, where she worked for the Internews Network, an international nonprofit dedicated to training journalists and advocating for press freedom.

Though Hidalgo originally planned to pursue a career in health care and criminal justice, the 2016 election inspired her to put her academic ambitions on hold and run for public office instead.

Hidalgo ran on a platform focused on flood control, criminal justice reform, and increasing transparency and accountability in local government.

[13] The election also switched majority control of Harris County Commissioners Court, over which Hidalgo presides, from Republicans to Democrats.

[1][16] During the COVID-19 pandemic, Hidalgo implemented public health measures early in an attempt to halt the spread of the coronavirus.

[17] Hidalgo has been credited with making voting easier in Harris County during the 2020 Texas elections and with increasing turnout among lower-propensity voters.

Because of her intervention, the federal government is investigating whether this proposed expansion, which could increase pollution and relocate people, violates any environmental and civil rights laws.

[22] In March 2021, concerns were raised over a contract awarded to Elevate Strategies, a company that was hired to do COVID-19 vaccine outreach.

Mark Jones of Rice University said, "This was an RFP [request for proposal] that was wired from the very start to go to Elevate Strategies to provide political money for Lina Hidalgo's supporters".

[28] Hidalgo was criticized after a March 2019 news conference in which she spoke in English and Spanish about the health implications of a massive chemical fire.