Master Theodoric, in Latin Magister Theodoricus (before 1328? – before 3 March 1381, active c. 1360–1380) was a Czech painter. He is the best documented Gothic painter in Bohemia. He was the favourite court painter of Charles IV, Holy Roman Emperor. and the first Bohemian painter whose name can be linked to a body of work. Theodoric is considered the chief representative of the phase of International Gothic known as "the Soft style". His masterpiece is the Chapel of the Holy Cross at Charles' newly completed Karlštejn Castle, near Prague, containing a large series of slightly over-lifesize half-length panel portraits of saints and other notable figures on a gold ground. The whole decoration of the chapel was commissioned in 1359 and completed over a number of years. The decoration of the Chapel of the Holy Cross was unique and unprecedented at the north of the Alps. Theodoric's oeuvre is not comparable to anything in European art after the mid-14th century (1360th).

He most likely came to Prague from the Rhineland (workshop of William of Cologne?) following a study trip to northern Italy in the 1350s. Pujmanová states that in about 1309 a sculptor described as 'Magister Theodoricus de Alemania', who could have been an ancestor of his and his brother - the painter Giletto, were active at the court of Charles II of Anjou in Naples. The waiting period for civic rights in Prague was three years, and the newly arrived person wasn't able to become a member of the fraternity of painters straightaway. The date he was entered in the list of the Prague painters' fraternity (Brotherhood of Saint Luke, established 1346), where he was described as a superior ("primus magister") and as "malerius imperatoris", is uncertain. Earlier it was assumed to be 1348, however it is possible that an honorary function was only offered to him when he executed the painting of the royal palace at Prague Castle in 1360.

In 1359 he is mentioned as "malerius imperatoris" and owner of a house in Hradčany in the Records of the Hradčany town. His house was mentioned once again in 1368 (house no. 185/IV above Úvoz on Hradčany Square. Between 1359 and 1367 he worked as the leading court painter of Charles IV in Prague and at Karlštejn Castle. The emperor called his painter and courtier Pictor noster et familiaris. In a special document of 28 April 1367, Charles IV certified that Theodoric's court and fields in the village of Mořina would be freed of all taxes and other charges. This privilege also applied to Theodoric's heirs and was granted in recognition of his decoration of the royal chapel at Karlštejn. Theodoric's court was mentioned again in 1381, when it was sold, in a letter by Wenceslaus IV. Mikuláš Mendl of Jílové, father of the goldsmith Jorg, and the goldsmith Jan Waczenser, sold the court to Zdena, the widow of Ješek Mráz of Lazevice. This document is the only one that establishes Theodoric's death before 8 March 1381 and indicates that he left no descendants.

Theodoric's magnum opus is a collection of panel paintings and wall paintings that were done on the commission of Charles IV for the Chapel of the Holy Cross at Karlštejn. All together, there are 129 works, all of saints, prophets, or angels. The National Gallery in Prague said that they "only few equals in the world: we believe that it is no exaggeration to say that they bear comparison with such artistic monuments and phenomena as the Arena in Padua, the churches at Assisi or Sta. Croce in Florence and the palace of the popes in Avignon."

Known for his bold and vigorous style, he is seen as a central figure in the development of Bohemian art. As many other Gothic painters, he used very bright and attention-grabbing colors and bold lines. He painted powerful figures in small frames, filling the viewer with the notion of monumentality. Famous for his use of light and reflection, he created the illusion of endless space in his work by allowing light to travel beyond the frame. Art historians have disagreed on several aspects of Theodoric's career. One historian noted that Theodoric was a "unique phenomenon" whose works could not be explained by stylistic evolution, as there were no precedents for his art work, making one believe that he may have been self-taught. Another scholar holds an opposite opinion—that he was influenced both by Italian and French contemporary art.

Theodoric followed on from the work of his predecessor in the service of Charles IV, the Master of the Luxembourg Genealogy, who painted the decoration of the imperial castle-palace at Karlštejn and the 'relic scenes' in the Chapel of the Virgin Mary between 1356 and 1357. This master was familiar with Franco-Flemish art of the 1350th and brought major innovations to mural painting in Bohemia. Several panel paintings ascribed to Theodoric's workshop repeat the typology of faces and patterns of movement in figures of the Genealogy. According to Homolka, two heavily damaged panel paintings of SS Peter and Paul from the Chapel of the Holy Cross could have directly originated in the workshop of the Master of the Luxembourg Genealogy, since the technology of their foundation layers is more typical of mural painting and thus differs significantly from the other paintings.

Theodoric's workshop carried out the unique overall decoration of the Chapel of the Holy Cross at Karlštejn Castle between 1360 and 1365. The chapel belongs to the tradition of lavishly decorated reliquary chapels that include the emperor chapel in Constantinople, Sancta Sanctorum in the Lateran Palace, or Sainte Chapelle in Paris. The decoration comprises 129 (originally 130) panel paintings in four rows, portraying the half-length figures of male saints, female saints and prophets who represented the 'Army of Heaven' guarding the relics kept in the chapel. Several of the picture frames had small openings into which reliquaries could be inserted. The depiction of the saints in the Holy Cross Chapel was directly linked to the veneration of their relics. The presence of relics of the Passion perhaps served to guarantee, that on his return Christ would descend to the chapel.

With the stylisation of the figures, the abandoning of the Gothic linear style and the modelling of the faces and drapery using light and shade, Theodoric's paintings surpass the preceding artistic style. It is clear that he was acquainted with French grisaille painting. The pictures can be attributed to Theodoric on the basis of analysing the underdrawings and comparing the execution of the painting. The drawn designs of the compositions, details of the faces and drapery, as well as the overall completion of the most important portraits in the Chapel of the Holy Cross were ascribed to Theodoric. Theodoric's brush drawing on the heads of the paintings is delicate and firm. On the draperies it is strong and energetic and overlaps onto the frame.