William Dargan Bridge, Cable-stayed bridge in Dundrum, Ireland.

The William Dargan Bridge is a cable-stayed bridge in Dundrum that crosses the Taney Road junction to carry the Luas Green Line trams. The structure features steel cables and a concrete deck, with an asymmetrical pylon rising above the roadway.

Construction started in October 2001 and was completed on 2 August 2002, when Minister for Transport Seamus Brennan remotely tightened a stress block before several hundred onlookers. The first Luas tram crossed during a line test on 11 February 2004. The bridge honours William Dargan, engineer of the Harcourt Street railway line whose alignment much of the Green Line follows.

Advertisements in local media invited name suggestions, and a committee including Luas chief architect Jim Quinlan and historian Briain MacAonghusa chose among them. Proposals ranged from William Dargan and cyclist Stephen Roche to Canon Harrington and Suas Luas, Irish for "up". The name was announced by Minister for Transport Seamus Brennan on 19 July 2004, when Fr Dan Dargan, the engineer's great-grandson, cut the ribbon.

The bridge is accessible to pedestrians via its northern side and offers views over the junction below. Visitors can watch trams passing and observe the traffic movement at the Taney Road crossing from this vantage point.

The 50-metre pylon is reinforced concrete, held by 13 pairs of high-tensile steel cables, and the deck is only 1.325 metres deep. The bridge won the Irish Concrete Society Infrastructural Category Award in 2002 and the Association of Consulting Engineers of Ireland President's Award for Excellence in 2003.