Little is known of Jocelin's early years, though it seems likely he was the younger son of a noble Anglo-Norman family living in south east Scotland and that he became a novice Cistercian monk at Melrose Abbey as a teenager in about 1149. He rose to become Prior of Melrose (the second most senior position at the Abbey) during the 1160s, and in 1170 Jocelin was appointed to be the 4th Abbot of Melrose Abbey. He held the post for just four years, on 23 May 1174 being elected to the more senior position of Bishop of Glasgow.
Bishop Jocelin is also remembered for his wider role in Anglo-Scottish relations. On 13 July 1174 King William I was captured by the English at Alnwick while trying to retake Northumbria. In December 1174 William, still a prisoner, signed the Treaty of Falaise, under which the King of Scots would henceforth be subordinate to the King of England: and the church in Scotland subordinate to that in England. In a neat political move, Jocelin sidestepped this, persuading the Pope Alexander to issue a Papal Bull which declared the Bishopric of Glasgow to be a "special daughter" of the Roman Church. In January 1176, Jocelin was called to York to appear before King Henry II of England and the Archbishop of York to confirm the subordination of the Bishopric of Glasgow to the Archbishopric of York, Jocelin was able to produce the Papal Bull and evade the terms of the Treaty of Falaise.
The Bull was confirmed in 1181 by Pope Lucius III when Jocelin travelled to Rome to appeal, on King William's behalf, against the King's excommunication by the Pope in an argument about the succession to the Bishopric of St Andrews. Jocelin negotiated an amicable end to the dispute. By now he was one of the most respected, and powerful, men in Scotland. He was frequently appointed by the Pope as Judge-delegate of the Papacy, to act on the Pope's behalf to resolve ecclesiastical disputes. He also witnessed 24 royal charters and 40 non-royal charters.
Jocelin accompanied King William to Woodstock near Oxford for his marriage to Ermengarde de Beaumont which took place on 5 September 1186. The marriage was blessed by Bishop Jocelin, who then escorted the new Queen back to Scotland. When the couple later had a son, the future Alexander II, it was Jocelin who performed the baptism. In April 1194 Jocelin again accompanied William to England, this time for talks with King Richard I which resulted in Quitclaim of Canterbury under which Scotland purchased back the rights given up under the Treaty of Falaise for the sum of 10,000 marks, which Richard badly needed to finance the Third Crusade.
Jocelin's had a particular impact on the settlement that grew up around his cathedral, Glasgow. In the late 1170s he obtained from King William a grant of burghal status for Glasgow, with a market every Thursday. And in the early 1190s he persuaded the king to granted Glasgow an annual fair, which still takes place today. Jocelin also became one of the greatest literary patrons of medieval Scotland, commissioning the Life of St Waltheof, the Life of St Kentigern and the Chronicle of Melrose. Jocelin died on St Patrick's Day, 1199, at Melrose Abbey, and was buried there.