Alfred Kastil (German: [ˈka:stil]; 12 May 1874, Graz – 20 July 1950, Schönbühel, Lower Austria) was an Austrian philosopher and Brentano scholar.

Kastil earned his doctorate in 1898 with the thesis Prinzipien der Aristotelischen Ethik (Principles of Aristotelian Ethics) under the supervision of Marty.

[7][9] Kastil and Kraus succeeded in beginning the editing and posthumous publication of the many drafts, lecture notes and letters left by Brentano.

"[11] McAlister regarded this as "an unfortunate scholarly practice because it effaces the traces of the development of Brentano's thought,"[11] (Kastil "identifies in the notes which passages have been changed" but "does not give the original text".

"[13] Peter Gollerm talks of Kastil as being, along with fellow philosopher Theodor Erismann, amongst the very few openly democratically minded opponents of the emerging right-wing authoritarianism and, from around 1929, of Nazism, within the secular Innsbruck faculty of the 1920s onwards.

[20][21] Kastil had also begun the preparation of Brentano's Grundlegung und Aufbau der Ethik, and, under her own editorship, Mayer-Hillebrand completed this work in 1952.

[22][23] Mayer-Hillebrand continued Kastil's work with Brentano's Religion und Philosophie (1954)[24] and Die Lehre vom richtigen Urteil (1956).