10 Oldest Characters In The Doctor Who Universe
3. The Face Of Boe
Estimated Age: Almost 5 billion years.
The Face Of Boe was one of the very first aliens introduced in the modern series of Doctor Who, and while not much is known about him, it's clear that he's powerful, wise, and incredibly ancient.
He popped up a few times opposite the Ninth and Tenth Doctors, and in Series 3's Gridlock, we actually saw him die, passing away peacefully in the city of New New York. This story is set in the year five billion and fifty three, which is nearly the same age as old Boe himself.
We know that Boe used to be Captain Jack Harkness (this was hinted at in the Series 3 finale, and has also been confirmed by Boe's creator, Russell T Davies), and since Jack is from the 51st century, we can pin Boe's age at almost five billion years.
Even if Captain Jack time-travelled around a bit - which he probably did - Boe is still easily in that billions range, which explains why he looks like a giant wrinkly nutsack.