In response to a significant increase in enrollment, a new senior high school was constructed in 1923–24 at 14th and Walnut Streets.

In 1973, eighth and ninth grade students began attending the newly constructed Parkview Junior High School.

The "Castle" was subsequently demolished, and the Walnut Street school exclusively housed seventh grade students until 1999.

Located just west of Finn S. at the corner of Parkview Drive and Ross Street, the current facility opened in August 1958.

The structure was modern for its era and featured an expansive facade of windows on the north and south sides.

The name change had been approved by a 3–2 vote on November 12, 2007, restoring the school's original name, effective after that year's freshman class graduated in 2011.

New Castle High School is a member of the Hoosier Heritage Conference and has programs in football, soccer, cross country, volleyball, tennis, basketball, gymnastics, wrestling, swimming, track, golf, softball, and baseball.