Sometimes we do thing intentionally sometimes unintentionally. But is there such thing such as unconscious intention in Buddhism (Theravada)?
We may be fooled into thinking there is unconscious intention, because we are ignorant in some moments of the nature of dependant arising of that moment, but in reality every moment is conditional arising, and intention is a component of such arising.
If we were to observe deeply every moment in life, and trace the origins of every thought and impulse, it will firmly convince us from our own experience that this is how it works at all times. Of course, initially this may only be possible on a retreat or while in meditation.
The Dhammapada begins by stating this,
manosettha manomaya manasa ce padutthena2
bhasati va karoti va
tato nam dukkhamanveti cakkamva vahato padam.
Verse 1: All mental phenomena have mind as their forerunner; they have mind as their chief; they are mind-made. If one speaks or acts with an evil mind, 'dukkha'3 follows him just as the wheel follows the hoofprint of the ox that draws the cart.
manopubbangama dhamma: All mental phenomena have Mind as their forerunner in the sense that Mind is the most dominant, and it is the cause of the other three mental phenomena, namely, Feeling (vedana), Perception (sanna) and Mental Formations or Mental Concomitants (sankhara). These three have Mind or Consciousness (vinnana) as their forerunner, because although they arise simultaneously with Mind they cannot arise if Mind does not arise. (The Commentary)
manasa ce padutthena (Verse 1) and manasi ce pasannena (Verse 2): Manasa here means intention or volition (cetana); volition leads one to the performance of volitional actions, both good and evil. This volition and the resultant actions constitute kamma; and kamma always follows one to produce results. Cakkhupala's blindness (Verse 1) was the consequence of his having acted with an evil intention in a previous existence and Matthakundali's happy existence in Tavatimsa celestial world (Verse 2) was the result of his mental devotion (manopasada) to the Buddha.
dukkha: In this context, dukkha mens suffering, or physical or mental pain, misfortune, unsatisfactoriness, evil consequences, etc., and rebirth in the lower planes of existence or in the lower strata of human society if born in the human world.
Certain actions like bowel movements, breathing, beating of the heart, etc. happen without consciousness. Also perhaps some limited form of physical and vocal action. These actions are morally neutral.
Also when you are in bhav’aṅga state (deep sleep) you are not conscious. Say you are a heavy snorer, then in this state this is unconscious action.
Also there can be muscle spasm which also can be unconscious.
Any action which followings any motivation either habitual (reactive) or premeditated will be conscious. This aspect is stressed in @Buddho's answer.