An infatuated young Sydney couple, who aspired to be a jihadi Bonnie and Clyde, have been found guilty of plotting a terrorist attack.

Sameh Bayda and his wife Alo-Bridget Namoa, both now 21, had denied conspiring between December 8, 2015 and January 25, 2016 to do an act in preparation for a terrorist act.

But after more than three days of deliberations, a NSW Supreme Court jury on Friday found them guilty of the plot said to involve detonating an improvised device, an incendiary device or using a bladed weapon.

Sameh Bayda and Alo-Bridget Namoa.

Namoa, who married Bayda in an Islamic wedding ceremony in 2015 when they were 18, had referred to the couple as a jihadi Bonnie and Clyde.