William Daniel Conybeare (June 7, 1787 - August 12, 1857) was an English geologist and paleontologist.

Conybeare was born in London and educated at Christ Church, Oxford. Having entered holy orders he became in 1814 curate of Wardington, near Banbury, and he accepted also a lectureship at Brislington near Bristol. During this period he was one of the founders of the Bristol Philosophical Institution (1822). He was rector of Sully in Glamorganshire from 1823 to 1836, and vicar of Axminster from 1836 to 1844. He was appointed Bampton lecturer in 1839, and was instituted to the deanery of Llandaff in 1845.

Attracted to the study of geology by the lectures of Dr John Kidd he pursued the subject with ardour. As soon as he had left college he made extended journeys in Britain and on the continent, and he became one of the early members of the Geological Society. Both William Buckland and Adam Sedgwick acknowledged their indebtedness to him for instruction received when they first began to devote attention to geology. In 1821 he distinguished himself by the description of a skeleton of the Plesiosaur, discovered by Mary Anning, and his account has been confirmed in all main points by subsequent researches. Among his most important memoirs is that on the south-western coal district of England, written in conjunction with William Buckland, and published in 1824. He wrote also on the valley of the Thames, on Elie de Beaumont's theory of mountain-chains, and on the great landslip which occurred near Lyme Regis in 1839.

His principal work, however, is the Outlines of the Geology of England and Wales (1822), being a second edition of the small work issued by William Phillips and written in co-operation with that author. The original contributions of Conybeare formed the principal portion of this edition, of which only Part I, dealing with the Carboniferous and newer strata, was published. It affords evidence throughout of the extensive and accurate knowledge possessed by Conybeare; and it exercised a marked influence on the progress of geology in this country. He was a fellow of the Royal Society and a corresponding member of the Institute of France. In 1844 he was awarded the Wollaston Medal by the Geological Society of London.

This article incorporates text from the public domain 1911 Encyclopædia Britannica.