Gonzalez was born in San Antonio. His father, Henry B. Gonzalez, represented the 20th from 1961 until his son took over in 1999. Charlie graduated from Thomas A. Edison High School. He received his bachelor's degree in government from the University of Texas at Austin in 1969, and then later earned his Juris Doctor degree from St. Mary's School of Law in San Antonio in 1972.

Gonzalez served as a technical sergeant in the Texas Air National Guard from 1969 until 1975. He then began practicing law until 1982 when he began rising through the ranks of the court system. He served first as a municipal court judge, then later as a judge in county and then district court, both of which are elected positions.

Henry Gonzalez had long groomed his son as his successor, so Charlie was well-positioned to run when his father didn't seek a 19th full term in 1998. He defeated his only major challenger, Republican James Walker, carrying 63f the vote and became only the fourth person to represent the 20th District since its creation in 1935; in fact, Charlie's first race was the first open-seat race in the district's 64-year history. He was reelected with no major-party opposition in 2000, unopposed in 2002, and with 63f the vote in 2004.

Gonzalez sits on the Energy & Commerce Committee. He is a former member of the Small Business Committee, the Select Committee on Homeland Security, and the Financial Services Committee. He is also a member of the Congressional Hispanic Caucus.

He is generally seen as less confrontational than his father, who once punched someone for calling him a communist. Between them, the father and son have served 44 consecutive years in Congress as of 2005; the only father and son combination to serve longer in the House has been the Dingells of Michigan, who have represented the state's 15th District for 72 consecutive years.