Peter Julian Ryan (born 30 October 1950) is a former Australian politician who was leader of The Nationals in Victoria from 1999 to 2014.

He represented the electoral district of Gippsland South from 1992 to 2015, and from 2010 to 2014 was the Deputy Premier of Victoria as well as the Minister for Rural and Regional Development.

One of his first acts as leader was to tear up the Coalition agreement and move the Nationals to the crossbenches as a separate party.

In February 2008 Ryan announced at a joint news conference with Baillieu that the Victorian Nationals and Liberals would join in a new coalition agreement.

After the Napthine Coalition government's defeat at the 2014 state election, Ryan stepped down as leader of the Nationals in Victoria, and was succeeded by Peter Walsh.