Born in Greenwich, London, Thomas was one of the most important English composers of sacred music before William Byrd (1543–1623). His style encompassed the simple Reformation service music and the great continental polyphonic schools whose influence he was largely responsible for introducing into English music.

Nothing is known of Tallis' education. He held a post at Dover Priory and in 1537 at St. Mary-at-Hill, London. His name appears in a list of persons who in 1540 received wages and rewards for services at the dissolution of Waltham Abbey in Essex. From Waltham he appears to have gone briefly to Canterbury and then to the Chapel Royal.

In a petition to Queen Elizabeth I, made jointly with William Byrd in 1577, he refers to having “served your Majestie and your Royall ancestors these fortie years,” but his appointment as a gentleman of the Chapel Royal can hardly have been before 1542.

On Jan. 21, 1575, Queen Elizabeth granted Tallis and Byrd the monopoly for printing music and music paper in England. The first publication under their license was a collection of 34 motets, 16 by Tallis and 18 by Byrd, entitled Cantiones sacrae, printed by T. Vautrollier in 1575. These Latin pieces, together with five anthems to English texts printed by John Day in his Certaine Notes . . . (1560–65), comprise all of his music that Tallis saw in print during his lifetime.

Tallis' Latin works include a modest, unnamed 4-part mass; a 5-part mass, Salve intemerata, derived from his antiphon of the same name; a 7-part mass; and two settings of the Magnificat. He also made two settings of the Lamentations of Jeremiah, the first of which is among his most celebrated works. Finally, among his Latin pieces two in particular are often cited as demonstrations of Tallis' supreme mastery of the art of counterpoint: the 7-part Miserere nostri, an extraordinary feat of canonic writing, involving retrograde movement together with several degrees of augmentation; and the famous 40-part Spem in alium, considered a unique monument in British music.

Tallis was one of the first composers to provide settings of the English liturgy. He has left settings of the Preces and Responses, the Litany, and a complete Service “in the Dorian mode,” which consists of the morning and evening canticles and the Communion Service. There are also three sets of psalms, and a number of anthems.

Tallis' keyboard music is regarded as substantial and significant. Of his 23 extant keyboard pieces, 18 occur in the mid-16th-century manuscript known as the Mulliner Book.