Orange County Sheriff's Office spokesman Jane Watrel said in an email Wednesday the suspect was in custody, but she didn't immediately have any other details.
West Orange High School Principal Doug Szcinski said on the school's Facebook page that a student injured in the shooting was taken to a hospital. He described the student as "alert." The principal said the school was on lockdown.
The Orange County Sheriff's Office earlier said on Twitter that police were investigating shots fired "near" the school.
The high school is located on the western side of metro Orlando.