Radiophobia- Fear of radiation, x-rays.
Ranidaphobia- Fear of frogs.
Rectophobia- Fear of rectum or rectal diseases.
Rhabdophobia- Fear of being severely punished or beaten by a rod, or of being severely criticized. Also fear of magic.(wand)
Rhypophobia- Fear of defecation.
Rhytiphobia- Fear of getting wrinkles.
Rupophobia- Fear of dirt.
Russophobia- Fear of Russians.