Liam Óg O'Flynn (Irish: Liam Ó Floinn, 15 April 1945 – 14 March 2018) was an Irish uilleann piper and Irish traditional musician. In addition to a solo career and as a member of Planxty, O'Flynn recorded with: Christy Moore, Dónal Lunny, Andy Irvine, Kate Bush, Mark Knopfler, the Everly Brothers, Emmylou Harris, Mike Oldfield, Mary Black, Enya and Sinéad O'Connor.
O'Flynn was acknowledged as Ireland's foremost exponent of the uilleann pipes and brought the music of the instrument to a worldwide audience. In 2007, O'Flynn was named Musician of the Year at the TG4 Gradam Ceoil Awards, considered to be the foremost recognition given to traditional Irish musicians.
He was born 15 April 1945 in Kill, County Kildare to musical parents. His father, Liam, was a teacher and fiddle player. His mother, Maisie (née Scanlan), who came from a family of musicians from Clare, played and taught piano. From an early age, O'Flynn showed musical talent, and was encouraged to pursue his interest in the uilleann pipes by the piper Tom Armstrong. At the age of 11, he began taking classes with Leo Rowsome. He was also influenced by Willie Clancy and Séamus Ennis. In the 1960s, he began to receive recognition of his talent, winning prizes at the Oireachtas Festival and the Fleadh Cheoil. During his early years, he was sometimes billed as Liam Óg Ó Flynn.