Diabolical Age is the third studio album by Norwegian black metal band Ragnarok, released on January 31, 2000, under Head Not Found record label.

It is the final album with vocalist Thyme (Dag Ronny Hansen).

Arcturus guitarist Knut Magne Valle was the engineer on the recording sessions.

All music and lyrics by Ragnarok, except lyrics for track 3 by Lillith Demona and music for track 8 written and performed by Jørgen Ø. Andersen.