Pieter van der Werff (1665 – 26 September 1722) was a Dutch Golden Age painter.

He assisted his older brother, Adriaen van der Werff.

[1] There is possible evidence he might have travelled to England to seek commissions as two portraits painted c.1709 of an unknown gentleman and unknown woman hang in the Victoria Art Gallery Bath, their alternative titles being John Churchill, First Duke of Marlborough and Sarah, Duchess of Marlborough.

[2] Whilst in England he may have had commissions from the Fairfax family – a long established Yorkshire Catholic family who owned extensive land and property in the county.

[3] Pieter was also the first recorded painter to use the pigment Prussian blue, with the earliest usage through painting a copy of his brother's painting The Entombment of Christ in 1709, using the pigment.