The title of "father of philosophy" is most often attributed to Thales of Miletus.

Thales, who lived in the 6th century BCE, was a pre-Socratic Greek philosopher, mathematician, and astronomer. He is considered by many to be the first philosopher in the Western tradition because he attempted to explain natural phenomena through reason and observation rather than mythology.

For more information you can check the following resources:

• World History Encyclopedia - Thales of Miletus
• Stanford Encyclopedia of Philosophy - Presocratics