The old church of Muthill survives in ruins. The W tower was built in the 12th century, which has carved work in two of the upper openings and on an exterior stringcourse. It has four external levels, each of the top two slightly narrower than the one below it, and has a crow-stepped roof facing east-west. According the MacGibbon and Ross (1896), the interior walls of the tower were 'plumb' and had 'neither corbels nor projecting courses to carry floors'. The remaining ruins of the main parts of the church come from reconstruction and alterations carried out in later centuries. As a result of these, the tower, which appears to have originally been free-standing, became enclosed on the north, east and south sides by the nave and aisles. The old church was condemned in 1825 and a new church begun on a different site in 1826. Access to the tower is through a doorway later inserted into the E face, but another doorway existed at some point in time on the W face, which was later blocked up. It is uncertain which of these is in the position where the original entrance point to the tower was located. Repair work was undertaken on the tower in the late-19th century and in the 20th century, especially on the upper exterior, where cracks had formed.

Although Muthill may have been an earlier relgious site nothing is securely known about this or the arrival of Culdees, who were first recorded at Muthill in the 12th century. The earliest ecclesiastical reference for Muthill comes between 1165 and 1171 when a certain Andrew, archdeacon of Muthill, witnessed a confirmation charter concerning the churches at Tullibody and Tullicultry. Several charters following this also show Muthill witnesses: ‘Patricio persona de Mothel’ (1168-1179), ‘priore Malgegill Meothill' and ‘Gillimichell persona de Moethel’ (1195-1198/1210), and ’Cormac Malpole prior Keldeorum persona de Mothell’ (about 1210) (see Reg. Cambuskenneth). In the Chartulary of the abbey of Lindores is an undated Quitclaim of Conveth from 'Malduueny, Rex scolarum de Mothel, et eiusdem loci scolastici'. Culdees were still in Muthill in 1235, when Clement bishop of Dunblane issued a confirmation, one witness of which was 'Mauricius prior Keledeorum de Mothel'. Muthill became part of the diocese of Dunblane, established in the 1150s. Specific reference to the church at Muthill occurs between 1195 and 1199, when Malise son of Earl Ferteth gave it to the abbey of Lindores. Following this a dispute arose between the bishop of Dunblane and the abbey of Lindores, as the bishop of Dunblane claimed that Muthill was an episcopal mensal church. The issue was settled in the first half of the 13th century, the bishop and his successors retaining the parsonage and one quarter of the vicarage. For the first year of Bagimond’s Roll (1270s) the church of Muthill was subject to a tax of 28 shillings and 8 pence. In the second year it was 28 shillings and 4 pence. Michael Ochiltree (later bishop of Dunblane) is said to have built the main body of the church, of which the ruins survive, probably between 1420 and 1429/30, when Ochiltree was dean, Muthill being part of his deanery.

Comparisons are made with the tower at Dunblane (former cathedral), the west tower of Dunning Church, and the west tower at Markinch. Unlike these three churches, however, no staircase was built into the tower at Muthill. The west tower of Muthill appears to have been originally detached from the church. This, along with the use of carved decoration consisting of a single string of diamond shapes, helps support the possibility of direct influence to/from Dunblane. It has also been suggested that Muthill may have been an ecclesiastical centre for the region before the 1150s, when Dunblane was established as the centre of the see. Gervase of Canterbury, probably early 13th century, recorded in his Mappa Mundi that the bishopric of Dunblane was occupied by Culdees which, if correct, would form another link between Muthill and Dunblane. Selgrave, in 1272, repeated the statement that Dublane had Culdees, though by this date it is unlikely that Dunblane Cathedral had such a religious group, a cathedral chapter having been established there in the later 1230s.

It is possible that the Earls of Strathearn were involved with the building of the church, as they were able to gift it to Lindores Abbey (something that was disputed by the Bishop of Dunblane who said it was an episcopal mensal church, forming yet another direct link between Muthill and Dunblane). The earliest known Earl of Strathearn, Malise I, first appears as a witness to various charters in the 1120s. He was with King David at the battle of Northallerton in 1138 and offered his son as a hostage in 1139, when peace between King David (of Scotland) and King Stephen (of England) was declared. Nothing is known, however, about his activities within his own earldom. He was still alive in 1141, but the date of his death is undocumented. The following Earl was Ferteth, who was earl by 1159 and died in 1171, but his specific relationship to Earl Malise I is unknown. Ferteth appears as a witness to several ecclesiastical charters and is named in a few royal charters. It has been suggested that he may even have been involved with the re-establishment of the bishopric in Strathearn. The third Earl, Gilbert (1171-1223), was the son of Ferteth. He was an active patron of the church, along with his brother Malise (another son of Ferteth). At a date prior to 1172, Earl Gilbert granted a series of lands to his brother, including Muthill. It was this Malise who gave the church of Muthill to Lindores Abbey sometime between 1195 and 1198.

In the Fasti Ecclesiae Scoticanae, the church of Muthill is said to have been dedicated to St Patrick. The present author has not found specific evidence to either support or dispute this claim.

Most writers have given a blanket twelfth-century date for the tower, but Fawcett, et. al. have suggested a date in the second quarter of that century. A date in either the second or third quarter of the twelfth century seems not unlikely.