Camillo Guarino Guarini (17 January 1624 – 6 March 1683) was an Italian architect of the Piedmontese Baroque, active in Turin as well as Sicily, France and Portugal.

[1][2] His work represents the ultimate achievement of Italian Baroque structural engineering, creating in stone what could be attempted today in reinforced concrete.

[6] Guarini rose quickly in the Theatine hierarchy, becoming first auditor, then superintendent of works, treasurer, lecturer in philosophy, procuratore, and finally provost in 1654.

During his tenure at the seminary, Guarini taught mathematics and philosophy and was commissioned with several architectural projects which he pursued over the next two years, including the design of the façade of Santa Maria Annunziata, as well as the adjacent Convento di San Vincenzo, the Church of San Filippo and a church for the Somaschi Fathers, a religious order founded in devotional service of the poor by Gerolamo Emiliani (1486–1537) in 1532.

[7][5] Guarini published his first literary work during his time in Messina, an elaborate political and poetic drama entitled La Pietà Trionfante.

In June 1662, Guarini received word that his mother was gravely ill and swiftly departed from Sicily to Modena to stay with her at the end of her life.

[4] In a fit of resignation, Guarini sharply accused the superior of the Theatine Order of mishandling resources and abandoned the project, leaving swiftly for Turin in the autumn of 1666.

[4] He designed a large number of public and private buildings in Turin, including the palaces of Charles Emmanuel II[10] (as well as his sister Louise Christine of Savoy), the Royal Church of San Lorenzo (1666–1680), most of the Chapel of the Holy Shroud (housing the Shroud of Turin; begun in 1668 by Amedeo di Castellamonte), the Palazzo Carignano (1679–85), the Castle of Racconigi and many other public and ecclesiastical buildings at Modena, Messina, Verona, Vienna, Prague, Lisbon, and Paris.

[1] Guarini's project appears to have been influenced by Bernini's proposals for the Louvre Palace in Paris (1665) and by Borromini's San Carlo alle Quattro Fontane.

Although, following the views of Aristotle, Guarino denies the existence of a vacuum, he describes and discusses Torricelli's barometer and barometric experiment with a glass tube closed at the top and filled with mercury.

The French astronomer and Catholic priest Ismaël Bullialdus is also mentioned numerous times in conjunction with Kepler, particularly when discussing the eccentricity of planetary orbits.

[17] Guarini attempts to discover the reason for this, using Euclidean geometry, triangulation and quadratura (quadrature), the available methods at a time that still predate the development of calculus and Newton's law of universal gravitation.

Guarini also theorizes that light travels from the Sun to the Earth in a vacuum (coniuncta soli est: unde vacua luce) until it reaches the atmosphere creating heat, wind and the movement of the ocean.

As he states in his Euclides adauctus et methodicus: «Thaumaturga Mathematicorum miraculorum insigni, vereque Regali architectura coruscat» - 'The magic of wondrous mathematicians shines brightly in the marvelous and truly regal architecture'.