The Soiscél Molaisse (/ˈsiːʃˌkɛl ˌmɒˈlæʃ/ SEESH-kel mo-LASH; 'Gospel of St. Molaisse') is an Irish cumdach (a type of ornamented metal reliquary box or carrying case for a holy book) that originated from an 8th-century wooden core embellished in the 11th and 15th centuries with metal plates decorated in the Insular style. Until the late 18th century, the shrine held a now-lost companion text, presumed to be a small illuminated gospel book associated with Saint Laisrén mac Nad Froích (d. 564 or 571), also known as Molaisse or "Mo Laisse". In the 6th century, Molaisse founded a church on Devenish Island in the southern part of Lough Erne in County Fermanagh, with which the cumdach is associated.

The shrine was constructed in three phases. The 8th-century original wooden box was embellished sometime between 1001 and 1025 with a silver frame under the direction of Cennefaelad, abbot of Devenish. This included embossed silver plates, a front piece depicting a cross, the figures and symbols of the evangelists, and series of Latin inscriptions. These additions form the bulk of the remaining object. A third phase, dated to the 15th century, incorporates further silver elements, although most have been lost. The Soiscél Molaisse is the earliest surviving cumdach, and with a height of just 14.75 centimetres (5+13⁄16 in), also the smallest.

The small size of the Soiscél Molaisse suggests that its companion text was meant to be carried as a pocket gospel book. That book was assumed to have been transcribed by Molaisse until the 19th century. The cumdach was held by the hereditary keepers O'Meehan family of Ballaghameehan, County Leitrim until the mid-19th century, and was acquired by the Royal Irish Academy in 1861, an acquisition supported by Lord Dunraven and George Petrie. It is now in the collection of the archaeology branch of the National Museum of Ireland on Kildare Street, Dublin.

The Soiscél Molaisse was constructed in three phases: the rather plain 8th-century wooden core has bronze casing that once held a small illuminated manuscript. This book is assumed to have been a Gospel and was traditionally associated with the 6th-century Laisrén mac Nad Froích, also known as St. Molaisse (d. 564 or 571), who founded the church on Devenish Island on Lough Erne in County Fermanagh, where the shrine was kept. The island still contains the remains of the monastery site, including the small Teampall Mór church, his cell, and the round tower in which the Soiscél Molaisse was kept over the centuries.

The book was lost sometime in the late 18th century, and almost nothing of its content or style was recorded. The 8th-century dating of the core and its manuscript is based on its dimensions, which would have been larger in earlier centuries. The object was heavily embellished and added to between 1001 and 1025 when bronze, copper and silver plaques were fastened with nails and rivets. Embossed silver plates were added in the 15th century, but are now mostly lost.

The 11th-century inscriptions on one of its long sides are signed by the metalworker Gilla Baíthín, along with the names of its commissioners "Cennfailad" (d. 1025, a successor of Molaisse who was an abbot at Devenish from 1001), and "Ua Sclan" (unidentified, possibly an administrator at the island). The dating of this phase to between 1001 and 1025 is based on the mention of Cennfailad, making it the oldest-surviving fully intact cumdach or "book shrine" (an elaborate ornamented metal reliquary box or case used to hold Early Medieval Irish manuscripts or relics). Baíthín would have worked during the Viking invasions of Ireland, and some Viking influence is apparent, such as the long, stringy bodies of the snake-like animals on the sides.

The shrine is oblong in shape and measures 14.75 centimetres (5.81 inches) high, 11.70 cm (4.61 in) wide and 8.45 cm (3.33 in) thick, making it the smallest of the extant Irish pocket-book Gospels. It is similar in size, type and function to the extant shrine for the 8th-century Book of Dimma, although the casing is much thicker, suggesting that it had either contained additional texts to the Gospels or had more illuminated pages. The manuscript was made from vellum parchment and contained text from the Gospels. Until the early 19th-century, the book was thought to have been written or owned by St. Molaisse; one late medieval text describes how it was "sent down to him from heaven while on a pilgrimage to Rome". The gospel was lost (and the cumdach damaged) in the late-18th century while on loan to McLoughlin, who was a priest from either County Sligo or County Roscommon.

The original 8th-century inner oblong box is made from yew wood. It was enshrined in the early 11th century with a cumdach made up of plain sheets of tinned bronze decorated with openwork silver and mountings. The Soiscél Molaisse has six sides: the front piece and its the reverse, two long sides, and two end sides. There are hinged fittings at both of the ends, to which a strap or chain could be attached for carrying during processions, swearing of oaths or other ceremonies.

The shrine is in relatively poor condition. The "roof" or "house-shaped" portions are lost, as are most of its jewels. The 15th-century additions, largely embossed silver plates, are now also mostly missing.

A ringed cross dominates the front face, with rectangular terminals decorated with insert panels of filigree and settings for semi-precious stones, which are lost except for one blue stone on the right side. The filigree on the arms of the cross is gilded and decorated with ribbon interlace. Some of the panels on the front face are missing, and those that remain are in bronze and silver-gilt, with gold filigree interlaced knotwork. Like other contemporary Insular objects found in nearby areas, such as the 12th-century stone figures on White Island on Lough Erne, and the Breac Maodhóg from Drumlane, County Cavan, it contains series of closely related figures.

The central panels depict the four Evangelists and their symbols and are placed in the spaces between a ringed cross. The Evangelists are depicted in profile or full front, standing behind large angular ribbons, and their names and representative figures are inscribed in Latin on each side of their silver frames. These read:

+ HO + MATH, + LEO + MARC, + AQUILA + IOHAN, + UITUL + LUCAS

Art historian Paul Mullarkey interprets these inscriptions as reading "the man (Matthew), the lion (Mark), the eagle (John) and the ox (Luke)". The figures are rendered in a style that closely resembles those on the cumdachs of the near-contemporary Stowe Missal and slightly later Breac Maodhóg. The scholar of medieval art, Roger Stalley, describes the somewhat squarish style of the figures in these works as "heavy and massive".

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  Detail of front panel; top left-hand panel (Matthew the Apostle, the man). The vertical Latin on the right reads Homo.
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  Top right-hand panel (Mark the Evangelist, the lion). The inscription on the right-hand side is translated as "Leo".
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  Lower left panel (Luke the Evangelist, the ox)
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  Lower right panel (John the Evangelist, the eagle). The inscription on the side translates as "Aquila".

Matthew wears a knee-length tunic containing a row of shields (peltae) in the La Tène style, positioned above a wide hem. His long hair curls into spirals which merge with the surrounding ribbon pattern. Mark is shown in profile with large, animalistic teeth and donkey-like ears, and also wears a half-length tunic with interlocking scrolls. Luke is represented by an ox, whose hind leg and tail lead into spiral patterns. John, as the eagle, has feathers, pointed ears, large talons and a broad tail. A tear-shaped drop, which may be blood, hangs from the coiled beak.