Alessandro Trasuntino (circa 1482, Bergamo, Lombardy – 13 June 1552, St. Angelo, Venice) was a notable Italian harpsichord maker and organ builder, recognized as one of the most significant Venetian craftsmen of the 16th century, alongside Domenico da Pesaro (circa 1500–1548) and Giovanni Antonio Baffo (1523–1581). The complexity of Trasuntino's biography has been a subject of extensive scholarly investigation by modern organologists, particularly due to the unusual nature of his surname, which has been misattributed by various individuals over time, including the infamous Italian antique dealer and fraudster Leopoldo Franciolini (1844–1920), who contributed to the proliferation of counterfeit and altered instruments in the European market. Name variations include: "Alessandro da gli organi," ALEXANDRI TRASVNITI, Traxentini, Trasuntini, Transuntino, Trasontini, Trasuntinis, Trazentinus.

The earliest documented mention of Trasuntino in Venice is from a patent application he filed in 1507 for a canal excavation device, indicating his involvement in the harpsichord trade as he was referred to as "Alessandro Traxentini dai Arpicordi." His strong connections to the church suggest that he may have been ordained as a priest, as evidenced by his purchase of a house in 1521 located next to the Trinity Church and Convent (now known as Santa Maria della Salute basilica). By 1542, he served as a non-resident rector at the Sant'Elena di Silea church. Surviving correspondence suggests that Trasuntino maintained a friendship with the influential writer and poet Pietro Aretino (1492–1556).

Fewer than twelve instruments are believed to be authentically crafted by Alessandro Trasuntino, which include harpsichords, virginals, and a single clavichord. Among these, only three harpsichords from the years 1530, 1531, and 1538 are definitively signed and authenticated. Although no organs attributed to Trasuntino are extant, there is archival evidence of his work, such as a restoration he conducted in September 1543 at the church of St. Nicolò. The legacy of Trasuntino's name has led to the emergence of numerous dubious instruments, including entirely fictitious makers associated with the “Trasuntini” name. Notably, [b]Bernardinus de Trasuntinis[/b] is recognized for the inscription "[i]Bernadinus de Trasuntinis fecit MDLXXIIII[/i]" found on the jackrail of a 1574 harpsichord at the University of Edinburgh's Musical Instrument Collection (previously owned by Dr. R. Mirrey). Research by Denzil Wraight suggests that this inscription is likely a forgery. Additionally, a virginal from 1532, signed by [b]Giovanni Francesco Trasuntino[/b] (Gio. Francesco Trazentinus), currently housed at the State Institute for Art Studies in St. Petersburg, Russia, has been identified by Wraight as the work of Bruneto Pontoni (circa 1499/1506–circa 1564), an Italian maker from Verona.

Trasuntino was known to have several assistants and disciples, including Venereo de Legge, also referred to as "Venerio da Lezze," who may have been his nephew, and most notably, [b]Vido Trasuntino[/b] (circa 1522–circa 1606), who was also known as Vito, Guido, and Giulio. Some researchers propose that he was not a blood relative but rather adopted Trasuntino’s name in admiration. Guido was a prolific builder, particularly celebrated for his "enharmonic" harpsichords that featured just intonation tunings beyond the standard twelve-tone octave. At least nine instruments attributed to Guido Trasuntino have survived, dating from 1560 to 1606, including harpsichords, virginals, and one archicembalo found in collections at Musikinstrumenten-Museum Berlin, Museo degli Strumenti Musicali, České Muzeum Hudby, Cantos Music Foundation, Cité de la Musique, and Museo Civico. Trasuntino passed away at the age of 70; his will, drafted in May 1542, allocated his estate between his "deceased brother Giacomo" and one of his disciples, "Franzesco Trasontini," adding further complexity to biographical research.

Alessandro Trasuntino's Instruments: - 1530 Harpsichord, Italy, private owner (the oldest known Venetian harpsichord) - 1531 Harpsichord, at Royal College Of Music, London, UK - 1537 Harpsichord, at Musikmuseet, Copenhagen, Denmark - 1537 Clavichord, owner and present location unknown - 1538 Harpsichord, at Musical Instruments Museum, Brussels, Belgium - 1547 Harpsichord, in Naples, Italy, formerly owned by Luigi Ferdinando Tagliavini (1929–2017) — first identified by Denzil Wraight in his Ph.D. thesis; made for the Duke of Ferrara, Ercole d'Este II (1508–1559), as indicated by the nameboard inscription, "[i]Her II Fer Dux IIII CRI[/i]". - 1604(?) Virginal, at Händel-Haus, Halle, Germany - 1742 Ottavino (small Virginal), at Musée De La Musique, Paris, France — identified as a counterfeit by Leopoldo Franciolini.