Diosdado Banatao (born May 23, 1946, Iguig, Philippines), popularly known by his nickname Dado, is a well-known Filipino serial entrepreneur and engineer working in high-tech industry. A three-time start-up veteran, he co-founded Mostron (PC Motherboards), Chips and Technologies (PC Chip Sets, eventually acquired by Intel), and S3 Graphics (originally 2D graphics chips, renamed to SonicBLUE). It is Silicon Valley folklore that he chose the company name S3 to mean "Start-up number 3".
He is a managing partner of Tallwood Venture Capital. Prior to Tallwood he was a venture partner with the Mayfield Fund. He has served on the board of directors and as chairman of several emerging companies, including Marvell Technology Group (MRVL), NewPort Communications (acquired by BRCM), and Cyras Systems (acquired by CIEN).
Banatao holds a Bachelor of Science degree in Electrical Engineering from Mapua Institute of Technology in the Philippines and a Master of Science degree in Electrical Engineering and Computer Science from Stanford University.