The Monrovia High School Symphonic Band is the premier concert ensemble at MHS. Members consist of brass, woodwind, and percussion students, most of whom also perform in the Marching Wildcats or other ensembles.

The MHS Symphonic Band has consistently earned ratings of Superior or Excellent at local and regional festivals. In February 2012, the Symphonic Band performed in the New York Wind Band Festival at world famous Carnegie Hall.

The Symphonic Band is directed by Mr. Daniel J. Magallanes.