a parliamentary and municipal burgh, and a sea-port town of Scotland, in the county of Renfrew, on the south bank of the Firth of Clyde, about 15 miles below Glasgow and 3 above Greenock. This place originally formed part of the adjoining parish of Kilmaclown, and consisted of the small village of Newark, so called from the barony of that name, which lay in its immediate vicinity. On a point of land projecting into the river, a little above the town, stands the ancient and now deserted castle of this barony. The ground on which the town stands was, in 1668, purchased from Sir Patrick Maxwell of Newark by the magistrates of Glasgow, with a view to provide a convenient harbour for the vessels belonging to the merchants of that city. In 1695 the place was detached from the parish of Kilmaclown, and with a few adjacent farms erected into a distinct parish. It was called New Port-Glasgow, or more commonly Port-Glasgow, a name simply expressing the design of its erection as the port or harbour of Glasgow. In 1775 it was created a burgh of barony; and by the Reform Act of 1822 it became a parliamentary burgh, uniting with Kilmarnock, Rutherglen, Dumbarton, and Renfrew, in returning a member.

The town is romantically situated at the foot of a hill, which, covered with wood and verdure, exhibits a beautiful object to travellers passing along the river. It is one of the most handsome and regularly-built seaport towns of Scotland. The streets are straight, and for the most part cross each other at right angles; whilst the houses, pretty nearly equal in size, and generally whitewashed, give to the whole a light and uniform appearance. The only buildings worthy of particular notice are the town-house and the parish church. Of these, the former is of plain but substantial workmanship, ornamented in front with a portico, resting on four massive fluted columns, surmounted with a handsome spire, which rises from the centre. The parish church, built in 1823, is square in form, and plain but handsome in appearance. A commodious chapel of ease was built in 1774. The other places of worship in the parish belong to the Free and the United Presbyterian churches. Port-Glasgow has also an endowed school, two parish schools, a public library, and two reading-rooms.

Attached to this port are two capacious harbours, substantially built, and completely sheltered. The first dry or graving-dock in Scotland was constructed here in 1769, and has since been improved at great expense. More recently a wet-dock has been constructed in the bay of Newark, which admits vessels drawing 25 feet of water. It is provided with spacious quays and commodious sheds, cranes, and other conveniences; and possesses extraordinary facilities for ingress and egress, owing to the great depth of water in the roads and entrance. With all these advantages, Port-Glasgow now affords shipping accommodation of a very superior description. The trade of the place was at one time chiefly carried on in ships belonging to Glasgow merchants; but the inhabitants have of late themselves become shipowners.

The foreign trade is chiefly with the West Indies and North America. It is the principal place on the Clyde for the importation of North American timber, for the reception of which it has large wood-ponds. The number of sailing-vessels registered at Port-Glasgow, 31st December 1857, was 54, tonnage 5706; of steam-vessels 8, tonnage 1192. In 1857 there entered the port 124 sailing-vessels, tonnage 51,324; and there cleared 44 sailing-vessels, tonnage 29,410; and 10 steam-vessels, tonnage 3695. The improvements in the navigation of the Clyde, and the rise of Greenock, have proved injurious to the prosperity of Port-Glasgow. Its coasting trade was at one time very considerable; but owing to the facility with which vessels of small burden now find their way up the river, nearly the whole of this branch has been transferred to Glasgow. The work of ship-building is carried on here to a considerable extent. Of late years a great number of iron steam-boats have been produced, some of them of the largest size. The manufacture of ropes and sail-cloth has been prosecuted for about a century. A considerable business is carried on in sugar-refining. Pop. in 1831, 5192; in 1841, 6973; and in 1851, 6986.