Stylistically, it is related to medieval German models, particularly from Westphalia and the Rhineland, but indirect influences from France are also discernible in the Gothic architecture of the cathedral.

In turn, its architecture influenced both local church building on Gotland and certain elements in the cathedrals of Linköping and Uppsala on mainland Sweden.

[4] Being a church for itinerant traders, it originally lacked a territorial congregation and was not subjected to any bishop or lord.

[2] Eventually several of the traders settled permanently in Visby, and formed a territorial congregation subjected, like all of Gotland, to the Bishop of Linköping.

[8] The church roof was also raised, adding a clerestory whose windows however only provided light for a new, large attic; the exterior was thus changed to appear as that of a basilica, without altering the interior at all.

Somewhat later, in 1572, the Diocese of Visby was established and Saint Mary's Church was promoted to the status of a cathedral.

The current wooden Baroque spires of these towers date from 1761, and the same year the gable of the great chapel was also rebuilt.

The most far-reaching changes were that the 14th-century clerestory was restored, the roofs of the aisles lowered, the removal of whitewash from the facade, the construction of a new sacristy and the renovation of the gable of the great chapel in a Gothic revival style.

The decoration of cathedral was also partially renewed, also in a Gothic revival style, with several new sculptures, wrought iron details and ridge turrets installed.

[10] The most noticeable change made during this renovation was that the great chapel was closed off from the main room of the cathedral.

Archaeologists believe that a medieval trading post for merchants from Germany was located nearby since the church was used by them; during archaeological excavations, enameled and gilded figures as well as 14th-century glassware from Syria has been unearthed nearby, indicating that goods from far away were handled in the vicinity of the church.

Its current main building dates from 1938 to 1939 and is built in a style inspired by traditional parsonages on the countryside of Gotland.

The south entrance is Baroque in style, and contains the faded monogram of Christian IV of Denmark and the coat of arms of Jens Hög, governor of Gotland 1627–1633.

Some of the changes during the 14th century, e.g. the new tracery windows and the addition of a clerestory not visible from the interior, may have been inspired from the construction of Uppsala Cathedral.

[9] Conversely, the architecture of the church is Visby, and in general a supply of limestone and stonemasons from Gotland to mainland Sweden, may have had an influence on elements both in Uppsala and Linköping Cathedral during the Middle Ages.

[1] The oldest parts of the cathedral are the lower part of the western tower (up to the upper lombard band), the gables of the original transepts (incorporated in the present north and south walls), the portal from the sacristy to the church and some of the pillars and vaults.

[6] During the Middle Ages, the facade was probably covered with whitewash with the exception of more finely sculpted details.

A lombard band runs around the chancel, the bay with the bridal portal and the west tower, a decoration which originally ran around the entire facade.

These openings, which were repaired and reconstructed at the turn of the last century, originally led to the attic of the cathedral.

[25] The facade of the great chapel is clearly distinguished from the rest of the building, and is also the most lavishly decorated, with its large un-decorated walls, its buttresses, pinnacles and gargoyles.

[26] The tabernacle frames on the buttresses next to the chapel portal are of a type quite common in continental Europe but in Sweden only known from Visby and Uppsala cathedrals.

[28] Much of the upper part of the facade of the great chapel dates from Haig's restoration, including the flèche and the large sculpture of Christ and its surrounding Gothic revival framing elements.

[31] The entrance to the sacristy dates from the restoration by Haig and its tympanum is decorated with a relief depicting Saint Nicholas.

[32] The former main north portal, which today connects the sacristy with the church and thus is not visible for regular visitors, is one of the oldest preserved parts of the cathedral.

[36] The most south-westerly pier still support a round arch from the first building period, the only visible remnant of the basilica.

[41] The keystones of the vaults are decorated with sculptures depicting the Lamb of God, the head of Christ and floral motifs.

[45] At that time it was replaced by a sandstone altarpiece made in Burgsvik on Gotland, today preserved in the cathedral in one of the aisles.

[50] Of more recent date is a nativity scene, displayed at Christmas annually, made in 1981 by Margaretha Ingelse.

[55] In addition, the church is also in possession of a harpsichord, placed in the chancel, which earlier belonged to harpsichordist Eva Nordenfelt [sv].

[58] There is also a memorial in remembrance of the sinking of a Danish-Lübeck fleet outside Visby in 1566 and the German admiral and mayor of Lübeck Bartholomeus Tinnapfel.