Robert fitz Martin (c. 10?? – c. 1159) was a knight from Devon whose father, Martin de Turribus, was the first Norman Lord of Kemes, in what had previously been the Dyfed part of Deheubarth. Fitz Martin inherited the Lordship of Kemes from his father, and founded St Dogmaels Abbey c. 1118. He was the first of the FitzMartin line. His descendants continued to hold lands in England and Wales until the 14th century.

Robert fitz Martin, was of a Frankish noble house of Blois, the great-grandson of the bellicose Eudus II, Count of Blois. ^{[citation needed]}He was born some time in the late 11th century to a knight of William the Conqueror, Martin de Turribus and his wife Geva de Burci, heiress of Serlo de Burci.

Martin had participated in the seizure of Rhys ap Tewdwr's lands, following the latter's refusal to acknowledge the suzerainty of William Rufus (despite having acknowledged the suzerainty of William the Conqueror), consequent attack on Worcester, and death in battle. Martin had sailed from Devon, and after landing at Fishguard, met little resistance (other than a skirmish at Morvil), becoming Marcher Lord of the area - Kemes (the name of the Lordship being a garbled version of Cemais, the name of the former Cantref); his Lordship stretched between Fishguard and Cardigan.

Geva de Burci's second husband was William de Falaise, with whom she had daughters, Emma and Sybil. "Emma de Falise married William de Courcy as her second husband. Earlier, she had been briefly married to William fitz Humphrey, but was evidently a widow soon after 1100 for, by 1106, she and her sister, Sybil, attested their father's charter without mention of their husbands. As a bride's possessions passed to her husband on marriage, he would normally attest before her but a widow acted in her own right."

Robert's half-sister, Emma de Falaise, married William de Courcy, a son of Richard de Courcy of Courcy-sur-Dives, Normandy. They received the manor of Stoke (renamed Stoke-Courcy, now Stogursey) in Somerset from William, and were grandparents of John de Courcy. This made Robert fitz Martin a brother-in-law of William de Courcy, who "was most active in royal administration during the first decade of the reign" of Henry I, to whom de Courcy was a royal dapifer.

Robert inherited property from his maternal grandfather, Serlo de Burci, in Somerset, Dorset, and Devon. Early in the reign of Henry I he succeeded to his father's Marcher Lordship of Kemes, setting his Caput baroniae at Nevern (Nanhyfer). Nevern Castle stood on a spur of the hill northwest of the church.

He married Maud Peverell and with her founded St Dogmaels Abbey between 1115 and 1119. Maude was a sister or daughter of William Peverel the Younger. The couple are not recorded as having any children. Not later than 1120, Robert Fitz Martin and Maud Peverel, his wife, granted to Savigny Abbey land at Vengeons (la Manche) which had belonged to William Peverel.

In 1134, he joined with the Norman lords in South Wales in resisting the sons of Gruffydd, and witnessed several charters of the Empress Maud, to whom he was adhered. During The Great Revolt 1136–1137 much of Kemes was reclaimed by the Welsh (once again becoming Cemais). Richard Fitz Gilbert de Clare, lord of Ceredigion, was ambushed and killed by the men of Iorwerth ab Owain. News of his death led to an invasion of Ceredigion by the sons of Gruffudd ap Cynan. Around Michaelmas they made an alliance with Gruffydd ap Rhys of Deheubarth. The combined forces made for Cardigan, and engaged the Normans at the Battle of Crug Mawr, two miles outside the town.