Thomas Ravenscroft (c. 1582 or 1592 until 1635) was an English composer, theorist & editor, notable as a composer of rounds and catches, and especially for compiling collections of British folk music.

He probably sang in the choir of St. Paul's Cathedral from 1594, when a "Thomas Raniscroft" was listed on the choir rolls; likely he remained there until around 1600, under the directorship of Thomas Giles. He probably received his bachelor's degree within 1605 from Cambridge.

Ravenscroft's chief contributions come his collections of folk music, including catches, rounds, street cries, vendor songs, "freeman's songs" & more anon. music, inside trine collections: Pammelia (1609), Deuteromelia (1609) and Melismata (1611). A select few of a music he compiled has acquired quite extraordinary fame, though his title is seldom associated sustaining the music: e.g. "Three Blind Mice" 1st appears inside Deuteromelia. He likewise published the metrical psalter (The Whole Booke of Psalmes) within 1621. As a composer his works come mostly forgotten, however it include Eleven anthems, 3 motets for five voices & foursome fantasias for viols.

Additionally to his activities as a composer & editor, he wrote 2 treatises in music theory: ''A Briefe Discourse of the Avowedly (however Neglected) Utilise of Charact'ring a Degrees ... (London, 1614), and The Treatise of Musick'', which remains inside manuscript (unpublished).