Sixto Hernández Serrano was born on April 6 in San Lorenzo, Puerto Rico.

Later, he completed his Juris Doctor at the Interamerican University of Puerto Rico School of Law, and received his licence as a CPA.

He is also licensed in real estate and is a member of the Puerto Rico Bar Association and the College of Certified Public Accountants.

After completing his bachelor's degree, Hernández worked as a tax auditor for the Puerto Rico Treasury Department at the District of Humacao.

In 2006, Hernández was appointed by Governor Aníbal Acevedo Vilá as an appeals judge.