Sébastien Érard (born Sebastian Erhard, 5 April 1752 – 5 August 1831) was a French instrument maker of German origin who specialised in the production of pianos and harps, developing the capacities of both instruments and pioneering the modern piano.
Érard was born at Strasbourg. While a boy he showed great aptitude for practical geometry and architectural drawing, and in the workshop of his father, who was an upholsterer, he found opportunity for the early exercise of his mechanical ingenuity. When he was sixteen his father died, and he moved to Paris where he obtained employment with a harpsichord maker. Here his remarkable constructive skill, though it speedily excited the jealousy of his master and procured his dismissal, almost instantly attracted the notice of musicians and musical instrument makers of eminence.
Before he was twenty-five he set up in business for himself, his first workshop being a room in the hotel of the duchesse de Villeroi, who gave him warm encouragement. He built his first pianoforte in 1777 in his Paris factory, relocating fifteen years later to premises in London's Great Marlborough Street to escape the French Revolution - his increasing fame and several commissions for the likes of Louis XVI and Marie Antoinette having placed him at risk.
Returning to Paris in 1796, he soon afterwards introduced grand pianofortes, made in the English fashion, with improvements of his own. In 1808 he again visited London, where, two years later, he produced his first double-movement harp. He had previously made various improvements in the manufacture of harps, but the new instrument was an immense advance upon anything he had before produced, and obtained such a reputation that for some time he devoted himself exclusively to its manufacture. It has been said that in the year following his invention he made harps to the value of £25,000. In 1812 he returned to Paris, and continued to devote himself to the further perfecting of the two instruments with which his name is associated. In 1823 he crowned his work by producing his model grand pianoforte with the double escapement. Érard died at Passy, located in the XVIe arrondissement on the Right Bank.