Ramsay, David (c. 1575–1660), clockmaker, was probably born in Fife, the second son of the three sons and two daughters of James Ramsay (d. 1580) and his wife, Elizabeth, eldest daughter of David Ramsay of Clatty. It appears that in the absence of his elder brother, George, David took possession of his brother's property in Lothian and court action was taken to evict him. He then went to France, where John Carnegie, writing to his brother from Paris on 10 January 1610, related how he had been through the palace and the town seeking clocks, which were both scarce and expensive; however, the king's clockmaker had promised to show him a very fine ‘reveil-matin’ clock, and Carnegie would take Ramsay's advice regarding its worth. Possible products of Ramsay's years in Paris are the very early watch by him, later housed in the Victoria and Albert Museum, with a small irregular octagonal case of gold and silver, with hinged covers, bearing engravings of the annunciation and nativity, and an oval gold watch in the French style, dated to between 1600 and 1610 and signed 'David Ramsay, scotus, me fecit', subsequently held in the British Museum. In later years he employed a French journeyman, Guillaume Petit. Some fourteen watches, all of fine quality and some with alarms or calendar dials, survive in various collections.

Writing long after the event, Ramsay's son, William, claimed that on the succession of James to the English crown in 1603:

he sent into France for my father, who was then there, and made him page of the bedchamber and groom of the privy chamber, and keeper of all his majestie's clocks and watches. This I mention that by some he hath been termed no better than a watch maker. … It's confest his ingenuity led him to understand any piece of work in that nature … and therefore the king conferred that place upon him.

Ramesey, preface

If correct, this would suggest that Ramsay returned to Paris. Certainly, however, David Ramsay made three watches for Henry, prince of Wales (d. 1612), between 1610 and 1612 (his bill of £61 was not paid until 1622), and the 'Book of ordinances made at the Establyshinge of Prince Henry … at Oatelands' named him as a groom of Henry's bedchamber (Sixth Report, HMC, 672b). In 1613 he was granted a pension of £200 per annum, and in the same year James I gave him a pension of £30. His 'clock watch with alarum', dating from about 1615, is remarkable for the smooth action of its hand-cut wheels and pinions. On 26 November 1618 he was appointed chief clockmaker to James, with fees and allowances. In July 1619 he was granted rights of residence in England.

Ramsay's interests in mechanics led him to apply for licences and patents for the manufacture and use of numerous inventions and engines: 'to plough without horses' in 1619; 'to make an engine invented by John Jack and David Ramsay, Page of the Bedchamber, to raise water', for draining land and mines; 'an engine to turn spits'; and others dealing with the manufacture of saltpetre and a scarlet dye. Ramsay's royal duties were evidently considerable. In 1616 he received £234 10s. for the supply and repair of clocks and watches for James I. In 1622 he received another payment of £232 15s. for repairing clocks at Theobalds, Oatlands, and Westminster, and for making a chime of bells at Theobalds.

No specific renewal of his appointment to Charles I has been found, but in January 1626 a warrant was issued to pay him £150 for coins to be given by the king on the day of his coronation. A large sum of money owing to him since the time of James I was paid in 1627—£441 3s. 4d. for work, plus £358 16s. 8d. 'in lieu of diet and bouche of court'—and in 1632 he received £219 for bills submitted during that year. At this time he was living variously in King Street and Cannon Row, running east from the parish church of St Margaret, Westminster. Ramsay's wife was English; her name is not recorded but their son William Ramesey was born on 13 March 1627. William was schooled at St Albans, Bushy, Westminster, and other places. His father could not grant his request to go to St Andrews University so he attended Edinburgh, but had to leave that city because of the plague and from April 1645 he lived in London. By profession he was a physician and astrologer.

When Charles granted a charter of incorporation to the Clockmakers' Company he nominated Ramsay as its first master, an office he held for a year from October 1632. It seems, however, that he was mostly absent from town as a deputy was elected who presided at the court meetings during that time. An incident involving Ramsay was recounted by the astrologer William Lilly. Ramsay was told of treasure buried under the floor of Westminster Abbey and in 1632 he was given permission by the dean to search for it. He employed a diviner, John Scott, to ply his hazel rod through the cloisters and saw it twitch when they reached the west side. Their labourers excavated a coffin, but as this was deemed to be too light to contain anything of value, it was returned to its resting place unopened, no doubt disappointing the crowd of onlookers, Lilly among them, who had gathered for entertainment.

In his later years, Ramsay fell into poverty—perhaps having ventured his money in some barren mine—and in 1641 his creditors had him imprisoned in Westminster Gatehouse. He petitioned the House of Lords for payment of six years' arrears of his pension as groom of the privy chamber, but it was 1645 before the committee for the advancement of money granted him one-third of the money arising from his discovery of delinquents' estates. His petition of 1645 referred to arrears of bills and wages due to him from the king and prince amounting to £2000, payment of which he 'forbeares to request till times are better: yet having lost favour of the King … by his residence in London he had been cast into prison'. The petition is marked 'Nothing done in it' (Sixth Report, HMC, 41b–42a). In 1651 a further petition was referred to the mint committee; the outcome is unknown. It seems that he was still in prison in 1651 when he hoped to gain from the sale of some secret way of dyeing cloth scarlet. His son William, in the dedication to his father of his Vox stellarum (1652), alludes to this impoverishment having given 'occasion to some inferior-spirited people not to value you according to what you both are by nature and in yourself'. By this time David Ramsay was free and living in Holborn, by the Wounded Hart, near the King's Gate.

Ramsay died in 1660, being described as of the parish of St Martin-in-the-Fields in the administration granted to William on 20 August that year (TNA: PRO, PROB 6/203, fol. 113). A petition of 1661, from Mary, widow of David Ramsay, who stated that she raised troops for the king's service 'at Duke Hamilton's coming into England', since which time she had been sequestered and plundered, may refer to his widow. In 1660 Captain William Partridge petitioned for the appointment as king's clock- and watchmaker in succession to David Ramsay.