Griffioen served two aces on her way to a 6-2 7-6 victory in a match lasting an hour and a half. Compatriots Esther Vergeer and Aniek van Koot will battle it out for gold tomorrow.
Griffioen said afterwards: 'I'm very happy, I had a tough draw here. Facing Esther (Vergeer) in the semis wasn't easy. I played well, but I couldn't beat her, so then you have only one chance left for a medal and you play a tough opponent, so I am very happy to win this one.'
It was a successful day for Griffioen, who then teamed up with Van Koot to secure a 6-4 6-3 win over Lucy Shuker and Jordanne Whiley in the semi-finals of the Doubles.
They will face Vergeer and Marjolein Buis in an all-Dutch final after the pair defeated Sakhorn Khanthasit and Ratana Techamaneewat 6-0 6-1.
The men's Singles final will be a mouth-watering showdown between top seed Stephane Houdet and defending champion Shingo Kunieda.
Frenchman Houdet overcame Maikel Scheffers 6-3 6-2, while Kunieda was a 6-2 6-2 winner over Ronald Vink.
However, Houdet and Doubles partner Michael Jeremiasz - the defending champions - were knocked out in the semi-finals by Sweden's Stefan Olsson and Peter Vikstrom, the silver medallists in Beijing four years ago.
Frederic Cattaneo and Nicolas Peifer of France progressed to the showpiece with a 6-3 6-2 success over second seeds Robin Ammerlaan and Vink.
Top seed David Wagner of the USA and Israel's Noam Gershony, the second seed, will meet in the Quad Singles final after they beat their compatriots Nick Taylor and Shraga Weinberg.
The Wagner/Taylor and Gershony/Weinberg combinations won gold and bronze in the Quad Doubles yesterday.