SS San Wilfrido was a 6,458 GRT steam-powered British tanker that was launched in February 1914 and sunk by a German mine less than six months later. Armstrong, Whitworth & Co Ltd built her on the River Tyne for the Eagle Oil Transport Co Ltd. San Wilfrido struck the mine in the North Sea on 3 August 1914, one day before Britain declared war on Germany. She was Britain's first naval loss of the First World War. This was the first of two Eagle Oil tankers to be called San Wilfrido. The second was the Empire ship Empire Cobbett, which Eagle Oil bought and renamed Sain Wilfrido in 1946.