English poet, mystic, and scholar in Latin and Hebrew, author of a Latin tragedy, Roxana (1597, published 1632), which the 18th-century critic Samuel Johnson thought was the finest Latin writing in England before John Milton's elegies.

Alabaster was educated at the University of Cambridge and in 1596 accompanied the Earl of Essex's expedition to Cádiz, Spain, as chaplain but became a Roman Catholic in 1597, consequently suffering intermittent imprisonment. When visiting Rome in 1609, he was denounced to the Inquisition because of his mystical writings. After much wavering he reverted to Anglicanism and became the king's chaplain in 1618. He also wrote an unfinished Latin epic, Elisaeis, glorifying Elizabeth I, as well as occasional poems, spiritual sonnets, mystically inclined prose works, and biblical commentaries. His sonnets are sometimes claimed to be the earliest religious lyrics in the Metaphysical style.