The Birthday of Manuel L. Quezon is a special non-working holiday in the Quezon Province in the Philippines. The holiday is celebrated annually on the 19th of August to commemorate Quezon’s birthday in 1878. Manuel L. Quezon, the second official President and the first elected President of the Philippines, was a significant national leader who played a significant role in establishing the Philippines' national language, making him known as the 'Father of the National Language'.

The birthday of Manuel L. Quezon is a day of remembrance and pride for the Filipino people. The day is filled with various activities honoring Quezon's contributions to the country. Annually, program activities like wreath-laying ceremonies at the Quezon Monument in Manila to mark the occasion are conducted, and talks and discussions about Quezon’s life and legacy often coincide with the celebration. Schools and other government institutions also conduct special activities to educate the youth about the contributions made by Quezon.

On a local level, in Quezon province, the day is even more elaborate, with parades, civic ceremonies, and cultural activities taking place. The Quezon Day celebration strengthens the values of nationalism and patriotism that Quezon himself espoused during his term as President. In the face of varied opinions and diverse ideologies, the day serves as a reminder for the Filipinos of Quezon’s famous mantra 'My loyalty to my party ends where my loyalty to my country begins.'