Colquhoun, a descendent of the Scottish Clan Colquhoun of Luss, was born in Dumbarton in 1745. Orphaned at the age of 16, his relatives sent him to America, setting him up in the lucrative commercial trade in Virginia. In 1766, the 21-year-old Colquhoun returned to Scotland, settling in Glasgow and going into business on his own in the linen trade. Ten years later, with the outbreak of the American Revolution, Colquhoun sided against the rebels and, along with 13 other local businessmen, funded a Glasgow regiment to contribute to the government’s war effort.
He built an estate in the West End (now part of Kelvingrove Park) and, on 22 July 1775, married his cousin Janet, the daughter of James Colquhoun, the Provost of Dumbarton. Between 1782 and 1784, Patrick Colquhoun himself served as the Lord Provost of Glasgow. He also founded the Glasgow Chamber of Commerce and Manufacturing during that time, and made himself the first chairman. He was awarded an honorary LL.D. by the University of Glasgow in 1797.
Colquhoun was an avid statistician, and collected economic data. He used this information to lobby the government on behalf of the country’s industries, particularly cotton and muslin. His findings formed the basis of numerous pamphlets and treatise that he wrote promoting legal reform and business generally. On one occasion, he traveled to Manchester and compiled statistics on the cotton trade. He presented his findings to Prime Minister William Pitt in 1789, but they were not acted upon because of the war with France. These activities brought Colquhoun increasingly into contact with the political sphere and to the attention of government and in 1785 he moved to London to seek a government position, and was appointed Magistrate in the East End.
Merchants were losing an estimated £500,000 worth of stolen cargo annually from the Pool of London on the River Thames. A plan was devised to curb the problem in 1797 by an Essex Justice of the Peace and master mariner, John Harriot, who joined forces with Patrick Colquhoun and utilitarian philosopher, Jeremy Bentham. Armed with Harriot’s proposal and Bentham’s insights, Colquhoun was able to persuade the West India Planters Committees and the West India Merchants to fund the new force. They agreed to a one-year trial and on 2 July 1798, after receiving government permission, the Thames River Police began operating with Colquhoun as Superintending Magistrate and Harriot the Resident Magistrate.
With the initial investment of £4,200, the new force began with about 50 men charged with policing 33,000 workers in the river trades, of whom Colquhoun claimed 11,000 were known criminals and “on the game.” The river police received a hostile reception by riverfront workers not wishing to lose their supplementary income. A mob of 2000 attempted to burn down the police office with the police inside. The skirmish that followed resulted in the first line of duty death for the new force with the killing of Gabriel Franks.
Nevertheless, Colquhoun reported to his backers that his force was a success after its first year, and his men had “established their worth by saving £122,000 worth of cargo and by the rescuing of several lives.” Word of this success spread quickly, and the government passed the Marine Police Bill on 28 July 1800, transforming it from a private to public police agency. Colquhoun published a book on the experiment, The Commerce and Policing of the River Thames. It found receptive audiences far outside London, and inspired similar forces in other countries, notably, New York, Dublin, and Sydney.
Significance for "modern" policing
Historians of policing credit Colquhoun’s innovation as a critical development leading up to Robert Peel’s “new” police three decades later. Along with the Bow Street Runners, the Marine Police Force was eventually absorbed by the Metropolitan Police in the 19th century. Colquhoun’s utilitarian approach to the problem – using a cost-benefit argument to obtain support from businesses standing to benefit – allowed him to achieve what Henry and John Fielding failed for their Bow Street detectives. Unlike the stipendiary system at Bow Street, the river police were full-time, salaried officers prohibited from taking private fees.
The idea of a police, as it existed in France, was considered an affront to the liberal English, particularly during this period of upheaval. For the government then, it was not only a matter of saving money, but that there was significant opposition and little support from political constituencies. In building the case for the police in the face of England's firm anti-police sentiment, Colquhoun framed the political rationale on economic indicators to show that a police dedicated to crime prevention was “perfectly congenial to the principle of the British constitution.” Moreover, he went so far as to praise the French system, which had reached “the greatest degree of perfection” in his estimation.
As impressive as Colquhoun’s salesmanship of the public police idea was, his main contribution is recognized as the introduction of crime prevention, or preventive policing, as a fundamental principle to the English police system. His police were to be a deterrent to crime by their permanent presence on the Thames. He came to this conclusion through viewing policing as a science, and in utilitarian fashion, attempted to press that science into the service of the national political economy. He published two dozen treatises on a variety of social problems, but the most significant is his 1797 A Treatise on the Police of the Metropolis.
The Marine Police Force continues to operate at the same Wapping High Street address. In 1839 it merged with the Metropolitan Police Force to become Thames Division; and is now the Marine Support Unit of the Metropolitan Police Service.
Consul of the Hanseatic League
Patrick Colquhoun was appointed as Resident Minister and Consul general by the Hanseatic cities of Hamburg in 1804 and by Bremen and Lübeck shortly after in the following as the successor of Henry Heymann, who was also master of the Steelyard (In German: Stalhofmeister). Colquhoun was valuable to those cities through the time of their occupation by the French until 1814 since he also provided the indirect communication between Northern Germany and Whitehall, especially in 1808, when the three cities considered their membership in the Confederation of the Rhine. His son James Colquhoun was his successor as Consul of the Hanseatic cities in London.
Scholar and historian Peter Linebaugh posits another persona of Colquhoun, i.e., the agent of often violent oppression wholly in the service of an industrialist and property-holding class in the earliest incarnation of socio-economic warfare in the Atlantic economy. The capitalist, investor regime needed a laboring under-class in thrall to subsistence wages to maximize profits. And, as farming the Commons  had been denied them, the increasingly desperate worker was feared by those keepers of the status quo. Linebaugh notes:
He was a planner of the trans-Atlantic cotton economy compiling stats of the workers, wages, factories, and imports in order to assist the prime minister and cabinet of England maximize profits from the cycle of capital in England, India, America, Ireland, Africa. That work was interrupted by the revolutions in France and Haiti.
In the 1790s he criminalized custom. He led the hanging of those committing money crimes. He led the apprehension of those in textile labor who re-cycled waste products to their own use. He organized political surveillance by spies and snitches of those opposing slavery. In addition to his Virginia cotton interests he owned shares in Jamaican sugar plantations. Financed by West India merchants and planters in 1798 Colquhoun established the Police Office. In 1800 Parliament passes the Marine Police Bill expanding and making official the police as a centralized, armed, and uniformed cadre of the state. His treatises on police inspired the foundation of police in Dublin (Ireland), Sydney (Australia), and New York (USA). 
- Clan Colquhoun and Patrick Colquhoun, "by David Minor"
- Significant Scots: Patrick Colquhoun, Electric Scotland. Retrieved 4 February 2007.
- George Stewart, Patrick Colquhoun, Curiosities of Glasgow citizenship, as exhibited chiefly in the business career of its old commercial aristocracy. Glasgow: James Maclehose, 1881. Retrieved on 7 February 2007.
- “Patrick Colquhoun: Statistics of Cotton Manufacture in Great Britain, 1771-1789; Significant Scots: Patrick Colquhoun, Electric Scotland. Retrieved 4 February 2007.
- Dick Paterson, Origins of the Thames Police, Thames Police Museum. Retrieved 4 February 2007.
- “Police: The formation of the English Police,” Encyclopædia Britannica, 2007. Retrieved 6 February 2007.
- T. A. Critchley, A History of Police in England and Wales, 2nd edition. Montclair, NJ: Patterson Smith, 38-39.
- G. D. Yeats, Biographical Sketch..., 44-45.
- "The Inclosure Acts"
- "The Ideal of Justice--Police and Plunder", by Peter Linebaugh
- Grant David Yeats, M.D. (Colquhoun's son-in-law), A Biographical Sketch of the Life and Writings of Patrick Colqhoun, London: G. Smeeton, 1818.
The 'Patrick Colquhoun' Thames Police Motor Launch 
Writings by Patrick Colquhoun
- Treatise on the Commerce and Police of the River Thames, London: H. Baldwin and Son, 1800.
- A Treatise on the Functions and Duties of a Constable, London: W. Bulmer and Co., 1803.
- Treatise on the Police of the Metropolis, London: Bye and Law, 1806.
- A Treatise on the Wealth, Power, and Resources of the British Empire, London: Joseph Mawson, 1814.