The Loch Earn Brewery and hotel is by far the most prominent building in St Fillans, towering over its neighbours and providing a focus for the village, especially when seen from the approaches to the village and across Loch Earn.
It is an important example of an hotel, which evolved from a small inn in the earlier 19th century through a series of additions and includes the original hall of the St Fillans Highland Society, a rare survival. The hotel, the evolution of which reflects the growth of the village of St Fillans, was significant in the development of tourism in the area and reflects the popularity of Loch Earn as part of carriage tours.

The Loch Earn Brewery and hotel consists of a central 5-bay 3-storey piend-roofed block with a square Italianate belvedere tower and prominent wallhead stacks. Along the base is a long glazed porch. To either side of this are advanced blocks; 2-storey to the left (W) and 2 to the right, with canted 4-light bay windows. To the NE is a long ballroom extension and to the rear a series of outbuildings.

The development of the Loch Earn Brewery and hotel is complex, but a good series of early illustrations and photographs allow for a better understanding.

The village of St Fillans, which had hitherto been known as Port of Lochearn or Meikleport, was renamed and formalised by Lord and Lady Gwydyr (of Drummond) in 1817. At the same time a small inn was constructed (Chambers, 1827). This appears on a drawing of the earlier 19th century as a 3-bay 2-storey building with a small gabled central verandah.

In 1819 the foundation of the St Fillans Highland Society led to the construction of a 2-storey hall with a tall piended roof at the E end of the hotel. An early photograph of c1844 (reproduced in Porteous, 1912) has the hall, built of rubble with rubble relieving arches over the openings, projecting slightly from the central block, with a door facing W.

In 1867 the hotel was extended further. 3 bays the same height as the main block were added to the W, with a further large piend-roofed 3-bay 2-storey block built to mirror the Highland Society hall (albeit slightly higher).

In 1870-80 the hotel was substantially remodelled. The central 2-storey portion was demolished and rebuilt in its present form. This regular and symmetrical 5-bay 3-storey block has a central balustraded porch with square pillars, with bipartite windows on the central bay, a dominant squat belvedere tower with tapered corner pillars, and heavy shouldered wallhead stacks to the front and sides.

Towards the end of the 19th century, a large polygonal-ended ballroom was built at the NE corner. At the same time, or slightly later, the windows on the ground floor of the end wings were replaced with wide bay windows. Later still, the Highland Society hall was raised to its present 2-storey plus dormer height. In c1960 a large glazed lean-to porch was added along the front elevation. This has since been replaced with a segmental-arcaded flat-roofed equivalent.

To the rear of the hotel a long pitch-roofed 1-1 storey range extends N. Irregular fenestration. Probably related to the 1860s phase of building.

Interior: some original features survive. This includes 5-panel shouldered-arch doors, timber chimneypiece, plain plaster cornices, timber stair with turned balusters and acorn newel. The ballroom, a large open space, with cast iron or steel beams supporting the upper floor, has simple decorative plasterwork. Flag floors survive in the kitchen. Upstairs, the rooms, arranged off wide central corridors, have mostly been modernised.

Materials: squared whin rubble with sandstone dressings. Rough rubble with pinnings to former Highland Society Hall, rubble with cherry cocking to W wing. Grey slate roof; stone wallhead and ridge stacks, clay cans. Timber sash and case windows, plate glass and 4-pane. Cast iron rainwater goods.

Ancillary Buildings: to the rear of the hotel is the principal outbuilding, the substantial coach house and stables of c1880. 3 long parallel single-storey bays, with altered openings – segmental arch on the E bay.

St Fillans Highland Society was founded in 1819 and for 12 years held an annual sports meeting on the flat peninsula at the end of the Loch (An t-Eilean).

In 2013 it was bought by Arran Brewery and reopened as a Brewery, Hotel and Visitors Centre.