Jean Germain I (or Joannes Goermans, as he signed his instruments) (1703 – 18 February 1777) was born in Geldern, Western Germany, and is known to have been working as a harpsichord maker in Paris by 1730, where he remained for the rest of his life.
He had seven children: his daughter Jeanne-Thérèse was a harpist and friend of Jean-Philippe Rameau's patron La Pouplinière.
He dealt mainly in Flemish ravalements of Ruckers instruments, popular in France at the time; the adaptations to the original harpsichords included knee levers for changing stops, and an enlarged range.
He made fortepianos after public taste started to favour them, and was an important early French maker of the instrument.
A notable oddity produced by Jacques Goermans in 1782 was a harpsichord with 21 keys to the octave using a tuning system suggested by Jean-Benjamin de la Borde.