Ardgowan House, Castle & Gardens is a privately owned late 18th-century mansion on the Firth of Clyde near Inverkip, Scotland.

[2] In 1403, King Robert III granted the lands of Ardgowan to his natural son, Sir John Stewart.

Their son Sir John Shaw-Stewart, 4th baronet, commissioned a design for a new house from the architect Hugh Cairncross.

[4] The gothic Chapel of St Michael and All Angels, built in the mid-19th century, is also on the estate,[5][6] but since 2010 it has lost its roof and is falling into ruin.

The house was in used in Ordeal by Innocence, a three-part BBC drama that was first broadcast during April 2018, and based on Agatha Christie's novel of the same name.