The successful candidate will receive 225,000 Euros of funding towards a drive in the 2018 Porsche Mobil 1 Supercup in Europe.
O'Keefe now faces a nervous wait to learn his fate while Porsche analyses the data before a winner is declared in the coming weeks.
“It was an amazing experience and certainly unique compared to anything I've done in my motor racing career so far,” said O'Keeffe.
“I was among a great group of young race drivers and it was amazing to experience the professionalism of Porsche Motorsport and see how it runs such an event.
“I have to thank Porsche for sending me over and allowing me to be involved in such a programme.
“I had my sights on reaching the Shootout ever since I starting racing with Porsche, and having come through 944 Challenge, GT3 Cup Challenge and Carrera Cup.
“I've really enjoyed my time being part of its Motorsport Pyramid. Making the next step to Porsche Mobil 1 Supercup would be a dream come true.
“It's an amazing prize on offer so now we have to wait until the winner is announced in a few weeks. Fingers crossed.”
VIDEO: Porsche Junior Shootout