Odhrán Mac Niallais (born 17 August 1992) is an Irish Gaelic footballer who plays for Gaoth Dobhair and, formerly, for the Donegal county team.

[3] Mac Niallais then starred in Gaoth Dobhair's first ever Ulster Senior Club Football Championship-winning campaign later in 2018.

In the Ulster semi-final defeat of Crossmaglen Rangers at Healy Park in Omagh, Mac Niallais scored four points, including one free.

[4] In the final against Scotstown, Mac Niallais was again awarded the "Laoch na hImeartha" (man of the match) after scoring four points, including three frees.

Called onto the field when Donegal were forced to make emergency reparations to the midfield following injuries to Rory Kavanagh and Neil Gallagher, Mac Niallais scored four points and collected the man of the match award in the Ulster semi-final against Antrim at Clones.

[21][22] Under the management of Rory Gallagher, Mac Niallais scored a 52nd-minute goal against Derry from a distance of 20 metres in the opening fixture of the 2015 National Football League.

[24] Mac Niallais scored a brace in the seven-point 2016 Ulster Senior Football Championship quarter-final victory over Fermanagh.

[35] In February 2020, he moved to Crouch End in England, close to Alexandra Palace, with the intention of playing football for North London Shamrocks.

[2] He is the younger brother of Ronan Mac Niallais, who managed Gaoth Dobhair to the 2023 Donegal Senior Football Championship final during his first year in charge.

[38] Squad as per Gaoth Dobhair v Scotstown, 2018 Ulster Senior Club Football Championship final, 2 December 2018