- Who is: King Jeongjo in Philosophy
- Who is it: Kim Kyu-won in Philosophy
- Who is it: Kukai in Philosophy
- Who is: Krishnamurti Jiddu in Philosophy
- Who is: KA Krishnaswamy Iyer in Philosophy
- Who is: King Sejong in Philosophy
- Who is it: Kishore Biyani in Philosophy
- Who is: Konstantin Tsiolkovsky in Philosophy
- Who is it: Kyeong-hee Choi in Philosophy
- Who is: Kang Hang in Philosophy
- Who is: Krishna Chandra Bhattacharyya in Philosophy
- Who is: Karel Čapek in Philosophy
- Who is: Kong Qiu in Philosophy
- Who is it: Kim Jwajin in Philosophy
- Who is: Kang Youwei in Philosophy
- Who is he: Karl Robert Eduard von Hartmann in Philosophy
- Who is: Kang Chol-hwan in Philosophy
- Who is it: Koji Nakanishi in Philosophy
- Who is: Karel Kosík in Philosophy
- Who is it: Ko Yun-hui in Philosophy
- Who is: Kyongju Son in Philosophy
- Who is it: Kojeve Alexandre in Philosophy
- Who he is: Knud Ejler Løgstrup in Philosophy
- Who is it: Kim Dae-jung in Philosophy
- Who is he: Karol Wojtyła in Philosophy
- Who he is: Klemens von Metternich in Philosophy
- Who is: Kwasi Wiredu in Philosophy
- Who is it: Kishore Mahbubani in Philosophy
- Who is: Kancha Ilaiah in Philosophy
- Who is he: Konstantinos Apostolos Doxiadis in Philosophy
- Who is: Karl Theodor Jaspers in Philosophy
- Who is: Kwame Nkrumah in Philosophy
- Who is it: Kim Iryop in Philosophy
- Who is: Kwon Jung-saeng in Philosophy
- Who is he: Konstantin Chernenko in Philosophy
- Who is: Krzysztof Michalski in Philosophy
- Who is it: Karyn Lai in Philosophy
- Who is it: Kuki Shuzo in Philosophy
- Who is it: Kyung-sook Shin in Philosophy
- Who is he: Karl-Otto Apel in Philosophy
- Who is: Karl Leonhard Reinhold in Philosophy
- Who is: Karl Rahner in Philosophy
- Who is: Karl Reinhold in Philosophy
- Who is: Kwame Anthony Appiah in Philosophy
- Who is: Kitaro Nishida in Philosophy
- Who is he: Karl Wilhelm Friedrich Schlegel in Philosophy
- Who is: Kurt Gödel in Philosophy
- Who is: Karl Jaspers in Philosophy
- Who is: Karl Popper in Philosophy
- Who is: Karl Marx in Philosophy
- What is it: Koinonia Nature in Philosophy
- What is it: Kathenotheistic Cosmogony in Philosophy
- What is it: Kosmarchy in Philosophy
- What is it: Kainogenesis in Philosophy
- What is it: Kynicism in Philosophy
- What is it: Krypteia in Philosophy
- What is it: Kairophany in Philosophy
- What is it: Kinesis Aisthesis in Philosophy
- What is it: Katabasis Myth in Philosophy
- What is it: Koinonia Ethos in Philosophy
- What is it: Katalepsis in Philosophy
- What is it: Kairothetic in Philosophy
- What is it: Kairokratia in Philosophy
- What is it: Katabasis Anabasis in Philosophy
- What is it: Krateia in Philosophy
- What is it: Kairologic in Philosophy
- What is it: Kalokagathia in Philosophy
- What is it: Katalysis in Philosophy
- What is it: Kynos in Philosophy
- What is it: Kainotomy in Philosophy
- What is it: Kybernology in Philosophy
- What is it: Kritarchy in Philosophy
- What is it: Kairosthesis in Philosophy
- What is it: Katharsis in Philosophy
- What is it: Katastasis in Philosophy
- What is it: Kosmogony in Philosophy
- What is it: Ktenology in Philosophy
- What is it: Kathenotheism in Philosophy
- What is it: Katabole in Philosophy
- What is it: Koinonikos in Philosophy
- What is it: Kausalgia in Philosophy
- What is it: Kryptos in Philosophy
- What is it: Kinesis in Philosophy
- What is: Kataphatic in Philosophy
- What is it: Koinê in Philosophy
- What is it: Katabasis in Philosophy
- What is it: Kairotopia in Philosophy
- What is it: Kénoma in Philosophy
- What is it: Kairopraxia in Philosophy
- What is it: Kinetics in Philosophy
- What is it: Kybernetes in Philosophy
- What is it: Kairology in Philosophy
- What is it: Kritik in Philosophy
- What is it: Kenosis in Philosophy
- What is it: Category in Philosophy
- What is it: Krasis in Philosophy
- What is it: Koinonia in Philosophy
- What is it: Kosmology in Philosophy
- What is it: Kierkegaardianism in Philosophy
- What is it: Kantianism in Philosophy
- What is: Keeping Virtue in Stoicism
- What is it: Kindling Wisdom in Stoicism
- What is it: Keen Insight in Stoicism
- What is it: Kind-hearted Virtue in Stoicism
- What is: Keeping Integrity in Stoicism
- What is: Knowing the Truth in Stoicism
- What is: Keeping Tranquility in Stoicism
- What is it: Kindling Virtue in Stoicism
- What is: Knowledge of Nature in Stoicism
- What is it: Kindness to Self in Stoicism
- What is: Keeping Equanimity in Stoicism
- What is: Knowledge of Reality in Stoicism
- What is it: Kindling the Inner Light in Stoicism
- What is: Keen Understanding in Stoicism
- What is: Knowing the Mind in Stoicism
- What is it: Kindred Spirits in Stoicism
- What is: Knowledge of Virtue in Stoicism
- What is: Knowledge of Self in Stoicism
- What is: Kindness to Others in Stoicism
- What is it: Kin (Kin) in Stoicism
- What is it: Keenness (Acumen) in Stoicism
- What is: Kind-heartedness in Stoicism
- What is it: Knowledge of Good and Evil in Stoicism
- What is: Knowing Thyself in Stoicism
- What is it: Knack in Stoicism
- What is it: Kingship in Stoicism
- What is it: Kinship in Stoicism
- What is it: Kantianism in Stoicism
- What is: Knowledge in Stoicism
- What is it: Kindness in Stoicism