Tener la cabeza en otro sitio

Tener la cabeza en otro sitio
 

Meaning I was thinking of something else, or I was absent-minded. Do you have an expression with "head" like my head was somewhere else.?

Yes that's it. More often we use mind instead of head.

GRACIAS POLI; De dónde viene Poli, de polifacetico de policia ?

I agree with Poli.

Tienes la cabeza en otro sitio.
Your mind is elsewhere.