Willielma Campbell, Viscountess Glenorchy (1741–17 July 1786) was a patroness of evangelical missionary work and founder of several chapels in Scotland, England and Wales.

Lady Glenorchy persuaded her husband to purchase the estate of Barnton, then up for sale by the Duke of Queensberry, providing her with a home four miles from the centre of Edinburgh.

She held evangelistic services in her Edinburgh home at Barnton open to both rich and poor, and also established several chapels in both Scotland and England.

[6] In 1772, soon after she came into her fortune following the death of her husband, Lady Glenorchy decided to found a chapel in Edinburgh with the intention of being in communion with the Church of Scotland.

Lady Glenorchy decided that "the Orphan-park is the most desirable" and feued part of the Edinburgh Orphan Hospital's grounds which lay between the Old Town and Calton Hill, adjacent to the Trinity College Kirk.

In 1773, Lady Glenorchy renovated the chapel in Strathfillan, Perthshire and, under the auspices of the Society in Scotland for Propagating Christian Knowledge provided an endowment for a minister.

To ensure that her favoured evangelical enterprises would flourish, she left much of her £30,000 estate to her chapels, to the SSPCK and to a fund for educating young ministers.

On the demolition of Lady Glenorchy's Church in 1844, the remains of Lady Glenorchy were removed to the family vault in St John's burying ground, but in 1859 they were laid to rest in the Richmond Place Chapel where a suitable vault had been built and where the marble tablet removed from the original Church was placed over the grave.