Hilda Lucia Solis (/soʊˈliːs/; born October 20, 1957) is an American politician and a member of the Los Angeles County Board of Supervisors for the 1st district. Solis previously served as the 25th United States Secretary of Labor from 2009 to 2013, as part of the administration of President Barack Obama. She is a member of the Democratic Party and served in the United States House of Representatives from 2001 to 2009, representing the 31st and 32nd congressional districts of California that include East Los Angeles and the San Gabriel Valley.

Solis was raised in La Puente, California, by immigrant farmers from Nicaragua and Mexico. She earned degrees from the California State Polytechnic University, Pomona and the University of Southern California and worked for two federal agencies in Washington, D.C. Returning to her native state, she was elected to the Rio Hondo Community College Board of Trustees in 1985, the California State Assembly in 1992, and the California State Senate in 1994. She was the first Hispanic woman to serve in the State Senate, and was reelected there in 1998. Solis sought to pass environmental justice legislation. She was the first female recipient of the John F. Kennedy Profile in Courage Award in 2000.

Solis defeated a long-time Democratic incumbent as part of getting elected to the U.S. House of Representatives in 2000, where she focused mainly on labor causes and environmental work. She was reelected easily to four subsequent terms. In December 2008, President-elect Barack Obama announced his intention to nominate Solis as the next Secretary of Labor. She took office after being confirmed by the United States Senate in February 2009, becoming the first Latina to lead one of the United States federal executive departments. There she focused on workplace safety issues and on strengthening compliance with wage and hour laws. In January 2013, Solis stepped down from her post as Labor Secretary.

Returning to the area of her upbringing, in April 2014, Solis formally announced a campaign for a seat on the non-partisan Los Angeles County Board of Supervisors. Solis won the seat outright in a June 3 election and was sworn in on December 1. As Supervisor, Solis successfully lobbied the state to allocate funds for the Exide battery plant cleanup. One of her areas of responsibility was Downtown Los Angeles, where her main priority was dealing with gentrification and the lack of affordable housing. She was unopposed for re-election as Supervisor, which took place in June 2018. She served one-year terms as county chair from 2015 to 2016 and again from 2020 to 2021.

Solis was born in Los Angeles, California, as the daughter of immigrant parents who had met in citizenship class and married in 1953: Juana Sequeira (b. 1926, from Nicaragua) and Raúl Solís (from Mexico). Her father was a Teamsters shop steward in Mexico and, after coming to the United States, worked at the Quemetco battery recycling plant in the City of Industry in the San Gabriel Valley. There he again organized for the Teamsters, to gain better health care benefits for workers, but also contracted lead poisoning. Her mother worked for over 20 years on the assembly line of Mattel once her children were all of school age, belonged to the United Rubber Workers, and was outspoken about working conditions. She stressed the importance of education and was a devout Roman Catholic. Her Catholic faith, she said, "is a part of my life. My faith is what motivates me."

Hilda Solis is the third oldest of seven siblings (four sisters, two brothers) and grew up in a tract home in La Puente, California. She had to help raise her youngest siblings, and later said of her childhood: "It wasn't what you would call the all-American life for a young girl growing up. We had to mature very quickly." She graduated from La Puente High School, where she saw a lack of support for those wishing to continue their education, including a guidance counselor who told her mother that "Your daughter is not college material. Maybe she should follow the career of her older sister and become a secretary." However, another counselor did encourage her to attend college, and even went to her house to help her fill out an application. She took her younger sisters to the library to get them to follow her lead.

She was the first of her family to go to college, being accepted into the Educational Opportunity Program (which assists low-income, first-generation college students) at California State Polytechnic University, Pomona (Cal Poly Pomona) and paying for it with the help of government grants and part-time jobs. She graduated in 1979 with a Bachelor of Arts in political science. She then earned a Master of Public Administration degree at the University of Southern California in 1981.

Solis served near the end of the Carter Administration in the White House Office of Hispanic Affairs, where she was editor-in-chief of a newsletter during a 1980–1981 Washington semester internship as part of her master's program. At the start of the Reagan Administration in 1981, she became a management analyst at the civil rights division of the Office of Management and Budget, but her dislike for Ronald Reagan's policies motivated her to leave later that year.