Stranorlar (Irish: Srath an Urláir) is a town, townland and civil parish in the Finn Valley of County Donegal, in Ireland. Stranorlar and Ballybofey (located on the other side of the River Finn) form the twin towns of Ballybofey–Stranorlar.

Evidence of ancient settlement in the area includes a number of ring fort and holy well sites in the townlands of Stranorlar, Mullandrait, Lough Hill and Admiran. Stranorlar's Church of Ireland church, St John's Church in Glebe townland, was built c. 1729. Isaac Butt (1813–1879), founder of the Home Rule movement, is buried in its churchyard.

In November 1922, during the Irish Civil War, a column of Anti-Treaty IRA irregulars from the 2nd Northern Division were captured at Dunlewey in west Donegal by the National Army and held in Drumboe Castle outside Stranorlar. On 14 March 1923, they were taken from the castle to the nearby Drumboe woods and summarily executed.

There is a memorial to the four men on Stranorlar's main street and, since 1924, there has been a commemoration march to the monument each year by republicans. The four executed men were:

The town is located at the junction of the N15 and N13 national primary roads. For nearly 100 years, Stranorlar was the headquarters of the County Donegal Railway system (originally the Finn Valley Railway), with services to Derry and Letterkenny via Strabane (near Lifford), to Ballyshannon and Killybegs via Donegal, and to Glenties. At its peak, the railway had 130 employees. The last train ran from Stranorlar in 1960. As of the 21st century, the nearest operational railway station is the Northern Ireland Railways station, Derry~Londonderry railway station, in Derry.

Stranorlar railway station was built by the Finn Valley Railway and opened in September 1863 and closed on 6 February 1960. The old railway station was demolished to make way for a new bus garage owned and run by Bus Éireann. As part of a series of millennium celebrations, the old clock from the railway station was restored and installed in a new clock tower which sits at the old pedestrian entrance to the railway station yard. The town is one of the two Bus Éireann depots in County Donegal.

The town is served by the Bus Éireann No. 64 (Derry/Galway) service which connects the town to Donegal Town, Ballyshannon, Bundoran, Sligo and Letterkenny. There is also a regular service to Lifford and Strabane. TFI Local Link routes 264 (Ballyshannon/Letterkenny), 288 (Ballybofey/Derry), 290 (Ballybofey/Letterkenny), 988 (Cloghan/Letterkenny) also service the area.

Stranorlar is home to St. Columba's College and Finn Valley College. The town is also home to two primary schools: St Mary's primary school, and Robertson National School.