So far, the latest I can find is Ali Qushji (died 1474). http://en.wikipedia.org/wiki/Ali_Qushji
Al Kashi I'd already read about.
From another link on askhistorians I'd found Mulla Sadra (1571/2 – 1640), though his focus seems more theological (though his existentialism is interesting): http://en.wikipedia.org/wiki/Mulla_Sadra
Thanks!
How major do you mean? There was Abdus Salaam from Pakistan who won the Nobel prize for physics in '79
https://en.wikipedia.org/wiki/Abdus_Salam
There may be some alive today. Scientists don't usually get a lot of publicity unless they are really famous like Hawking.