Students attending Tesoro are within the cities of Rancho Santa Margarita, Las Flores, Ladera Ranch, Coto de Caza and Mission Viejo.

In 2015, Tesoro Performing Arts Department (orchestra, band, and choir) was one of the top competitors vying for a Grammy.

The choir has performed extensively throughout Southern California, as well as Spain, Germany, Austria, Switzerland, England, Ireland, and Mexico.

In 2005, the Titans became Back-To-Back Division IX CIF Champions after beating Northwood High School for the second time that season.

[citation needed] In 2004, The Tesoro Women's soccer team captured their first CIF victory with a 1-0 win over Buena High School.

They went on to make it to the CIF Southern Section championship game at the Angel Stadium of Anaheim, and lost to Long Beach Polytechnic High School.

[citation needed] The 2009 varsity basketball team became the South Coast League champions, and also went to the CIF Southern Section championship game at the Honda Center where they beat Ventura High School.

[citation needed] According to the California Department of Education Policy and Evaluation Division, Tesoro High School's 2008 API score was 836, a 21-point growth from 2007 which was 815.

Tesoro opened in 2001 serving Las Flores, Rancho Santa Margarita, Ladera Ranch, Coto de Caza, and Dove Canyon.

The modern school is built in a canyon at the end of the 241 toll road in between Las Flores and Coto de Caza south of Oso Parkway.

Over the summers of 2014 and 2015, a group of Tesoro students painted most of the school hallways, themed by subject and adding a unique, vibrant mood to the walls.

The team defeated Woodbridge High School, and proceeded to the state finals competition in San Jose, CA.

In 2005, two star football players, Scott McKnight and Sam Smith, were expelled for writing explicit and graphic death threats that involved sexual actions.

[23][24] The students wrote the journals for a class assignment that the teacher, to whom they were referring, collected and then promptly notified school officials.

[25] In 2008, seniors Omar Khan and Tanvir Singh were arrested and indicted on several felony and misdemeanor charges, including burglary, identity theft, computer abuse, and records tampering in an elaborate cheating scandal.