The rocks upon which the Skerries Lighthouse stands are at the end of a low tract of submerged land North-East of Holyhead which lies directly in the path of many of the major shipping lines from Liverpool and Ireland. The lighthouse gives a guide to passing shipping and a warning of the dangerous rocks.

A light was proposed on the Skerries as early as 1658, by Henry Mascard, a private speculator who saw the lucrative possibilities of the tolls that could be levied on the site, but this was opposed by Trinity House, as was a petition in 1705 from the Irish Sea Traders. In 1714, William Trench, who actually held the lease of the Skerries was granted a patent by Queen Anne for the building of a light. For a Crown Rent of £5 a year, Trench was given the right to levy dues of one penny per ship and twopence per ton of cargo, but far from being the profitable venture which he envisaged, the Skerries proved to be his ruin. When the light was first kindled on 4th November 1717, William Trench was wealthy but traders and mariners evading payment of dues caused him to fall heavily into debt. He died in 1729 a ruined man.

After Trench's death the lease passed to his daughter, and because of the nature of the debt, an Act of Parliament was passed to give his family sole claim to the Skerries. This act caused a great deal of embarrassment to Trinity House. In 1834 when an attempt was made to purchase the patent for this lighthouse, the proprietor, Morgan Jones, asserted that under this Act he was absolved from any responsibility to sell. For five years after the Act of 1836 which empowered Trinity House to purchase all private lighthouses, he opposed the purchase, the Skerries by this time being an extremely profitable light. It was finally purchased by Trinity House in 1841 for over £444,984, the last privately owned lighthouse in the British Isles to be bought by Trinity House.

The original coal-burning grate which surmounted the tower was replaced in 1804 by an oil lamp, and was subsequently converted to electric operation in 1927. The lighthouse was converted to automatic operation and demanned in 1987 and is now remotely monitored and controlled from The Trinity House Operations Control Centre at Harwich. The keeper's cottage, recently restored, is the oldest purpose-built keeper's accommodation in the world.