Phillips was born on October 15, 1953, in Southampton, England. He studied at St. John's College, Oxford University, as an organ scholar. By the time he graduated in 1975, he had gained a grounding not only in choral and organ music but in music history, studying with two of the leading British musicologists of the day, Denis Arnold and David Wulstan. In 1973, Phillips assembled a group of singers from Oxford and Cambridge to perform Renaissance music and named them the Tallis Scholars in honor of English Renaissance composer Thomas Tallis. The term "Scholars" was not merely fanciful, for the singers were all choral scholars from the various colleges of the two universities. Phillips held teaching posts at Oxford, the Royal College of Music, and Trinity College of Music, but the activities of the Tallis Scholars expanded after they established themselves formally in 1978. The group began a touring schedule that has taken them not only around Britain but often to continental Europe, Asia, and the U.S., which they had visited more than 60 times by the mid-2010s.
By 1988, Phillips had resigned his teaching posts, but he still found time to do research on early sacred music, to write several books, and to appear on several British television and radio programs. With Steve Smith he founded the Gimell label, at first exclusively as a recording arm of the Tallis Scholars; the clean sound of the label's recordings has exerted a major influence on the sound of Renaissance choral recordings generally. Phillips' activities as a conductor have also expanded beyond his leadership of the Tallis Scholars. He has led the Collegium Vocale Ghent, the Netherlands Chamber Choir, and Markell's Voices of Novosibirsk, Russia, among others. Phillips has been energetic in expanding the repertory of Renaissance choirs through new commissions from composers including Eric Whitacre, Nico Muhly, and John Tavener, a close personal friend; before his death, Tavener wrote for the choir a Requiem mass that was performed to mark the 100th anniversary of the outbreak of World War I.
Phillips has been a prolific recording artist who has led not only the Tallis Scholars but also other choirs on labels other than Gimell. With the Tallis Scholars, he released in 2019 a recording of Josquin's Missa Mater Patris and Noel Bauldewyne's Missa da Pacem on Gimell. ~ James Manheim, Rovi