Hadith studies (Arabic: علم الحديث ʻilm al-ḥadīth "science of hadith",also science of hadith, or science of hadith criticism or hadith criticism) consists of several religious scholarly disciplines used by Muslim scholars in the study and evaluation of the Islamic hadith—i.e. the record of the words, actions, and the silent approval of the Islamic prophet, Muhammad.

Determining authenticity of hadith is enormously important in Islam because along with the Quran, the Sunnah of the Islamic prophet—his words, actions, and the silent approval—are considered the explanation of the divine revelation (wahy), and the record of them (i.e. hadith) provides the basis of Islamic law (Sharia). In addition, while the number of verses pertaining to law in the Quran is relatively few, hadith give direction on everything from details of religious obligations (such as Ghusl or Wudu, ablutions for salat prayer), to the correct forms of salutations, and the importance of benevolence to slaves. Thus the "great bulk" of the rules of Islamic law are derived from hadith, rather than the Quran.

There are three primary ways to determine the authenticity (sihha) of a hadith: by attempting to determine whether there are "other identical reports from other transmitters"; determining the reliability of the transmitters of the report; and "the continuity of the chain of transmission" of the hadith.

Traditional hadith studies has been praised by some as "unrivaled, the ultimate in historical criticism", and heavily criticized for failing to filter out a massive amount of hadith "which cannot possibly be authentic".