Lethlobar mac Echach (died 709) was a Dál nAraide king of the Cruthin in Ulaid, an over-kingdom in Ireland.
[1] He belonged to the main ruling dynasty of the Dál nAraide known as the Uí Chóelbad based in Magh Line.
He succeeded to the throne upon the assassination of Cú Chuarán mac Dúngail Eilni (died 708) of the Eilne branch of the family in 708.
The annals record his death at the battle of Dul in Magh Eilne, between the rivers Bush and Bann in modern County Antrim, Northern Ireland.
[3] Lethlobar's daughter Barrdub was said to be a wife of Bécc Bairrche mac Blathmaic (died 718) a Dál Fiatach King of Ulaid.