- Kinship (Islamic law)7
- Kirmānī, Maḥmūd ibn Muḥammad, 1329?-1404 or 1405. Farāʼiḍ al-ījāz1
- Kirmāstī, Yūsuf ibn ḥusayn, d. 1500. Wajīz fī al-uṣūl2
- Kisāʼī, ʻAlī ibn Ḥamzah, -804 or 8051
- Kitāb (Sībawayh, ʻAmr ibn ʻUthmān)3
- Kitāb fī al-fiqh al-Shāfiʻī1
- Knowledge, Theory of (Islam)8
- Korea3
- Kufr (Islam)1
- Kumayl ibn Ziyād, 633 or 634-7012
- Kurds1
- Kāfiyah (Ibn al-Ḥājib, ʻUthmān ibn ʻUmar)108
- Kāfiyajī, Muḥammad ibn Sulaymān, -1474. Sharḥ al-Iʻrāb ʻan qawāʻid al-iʻrāb1
- Kāfī (Kulaynī, Muḥammad ibn Yaʻqūb)15
- Kāfī al-mubtadiʼ min al-ṭullāb (Ibn Balabān, Muḥammad ibn Badr al-Dīn)2
- Kāfī fī al-ʻarūḍ wa-al-qawāfī (Tibrīzī, Yaḥyá ibn ʻAlī)1
- Kāshī, Jamshīd ibn Masʻūd, -approximately 1436. Miftāḥ al-ḥussāb1
- Kāshī, Jamshīd ibn Masʻūd, -approximately 1436. Sullam al-samāʼ1
- Kāshī, Yaḥyá ibn Aḥmad. Qarah ḥāshiyah3
- Kātī, Ḥusām al-Dīn al-Ḥasan, -1358 or 1359. Qāla aqūl1