Gregorski assumed the interim position on Dec. 1, as the district worked to identify a candidate to replace outgoing Superintendent Lance Hindt.
Hindt announced his resignation in May amid accusations of bullying and plagiarism in his past.
Gregorski is a 26-year public school veteran, first teaching in the classroom before serving as an assistant principal, principal, and then assistant and deputy superintendent.
The district said in a statement Monday that Gregorski has "played an integral role in laying the groundwork for student learning in Katy ISD through his supervision of the School Leadership and Support Department, Human Resources and the Athletics Department."
Per Texas law, Gregorski had to wait a 21-day period before officially assuming the position.