Schoolchildren, worshippers and city officials are involved in the St Mungo celebrations.
At noon yesterday, The Archbishop of Glasgow Philip Tartaglia led a Mass of St Mungo in St Mungo's Church, Townhead.
A St Mungo service was also held in Glasgow Cathedral yesterday evening.
On Saturday, Archbishop Tartaglia and Glasgow Cathedral minister Laurence Whitley read from Vita Kentigerni – the life of St Mungo – in the city's Mitchell Library.
The Glasgow Russian children's choir performed at the event with members of the St Mungo Singers, giving visitors a taste of the opening of medieval vespers, or evening prayers.
St Mungo, who founded Glasgow, was one of the most important figures in the church in the 6th and early 7th Centuries.
Glasgow Cathedral stands on the spot where he was buried and his remains are said to rest in the crypt.
St Mungo's four religious miracles are represented in Glasgow's coat of arms
His life inspired the phrase: "Here is the bird that never flew, here is the tree that never grew, here is the bell that never rang, here is the fish that never swam."
The annual event is organised by Glasgow Churches Together and Glasgow Cathedral, with city council backing.
The celebrations ends on Saturday, when the Friends of Glasgow Cathedral hold a service at St Mungo's tomb.