Aquí aparece fuera del listado de óperas. Lo que no sé es si es algo que aún se discute, o hay unanimidad al respecto.
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http://opera.stanford.edu/Mozart/main.html
Operas
The dates and locations are those of the premieres; when there was a substantial delay between composition and performance, the estimated year of completion or last composition is also given. Köchel catalog numbers are the traditional ones, with revised catalog numbers in parentheses.
Apollo et Hyacinthus, K.38 (13.5.1767 University of Salzburg) (intermezzo)
La finta semplice, K.51 (KE 46a) (1.5.1769 Archbishop's Court, Salzburg)
Bastien und Bastienne, K.50 (K.46b) ((?) 10.1768 Dr. Mesmer's House, Vienna; 2.10.1890 (or 20.10.1890?) Architektenhaus, Berlin)
Mitridate, Rè di Ponto, K.87 (K.74a) (26.12.1770 Teatro Regio Ducal, Milan)
Ascanio in Alba, K.111 (17.10.1771 Teatro Regio Ducal, Milan)
Il sogno di Scipione, K.126 ((?) 1.5.1772 Archiepiscopal Residence, Salzburg)
Lucio Silla, K.135 (26.12.1772 Teatro Regio Ducal, Milan)
La finta giardiniera, K.196 (13.1.1775 Redoutensaal, Munich)
Il rè pastore, K.208 (23.4.1775 Archiepiscopal Residence, Salzburg)
Zaide, K.344 (K.336b) (1779; 27.1.1866, Frankfurt) (incomplete)
Idomeneo, ossia Ilia ed Idamante, K.366 (29.1.1781 Court Theatre, Munich) (Idomeneo, Rè di Creta)
Die Entführung aus dem Serail, K.384 (16.7.1782 Burgtheater, Vienna)
L'oca del Cairo, K.422 (1784; 4.1860, Frankfurt) (fragment)
Lo sposo deluso, ossia La Rivalità di tre donne per un solo amante, K.430 (K.424a) (1784) (fragment)
Der Schauspieldirektor, K.486 (7.2.1786 Schönbrunn Palace, Vienna)
Le nozze di Figaro, K.492 (1.5.1786 Burgtheater, Vienna)
Il dissoluto punito, ossia il Don Giovanni, K.527 (29.10.1787 Nationaltheater, Prague)
Così fan tutte, ossia La Scuola degli Amanti, K.588 (26.1.1790 Burgtheater, Vienna)
La Clemenza di Tito, K.621 (6.9.1791 Nationaltheater, Prague)
Die Zauberflöte, K.620 (30.9.1791 Theater auf der Wieden, Vienna)
In addition to the operas listed above, Mozart composed a few
other vocal dramatic works and incidental music, as follows:
Die Schuldigkeit des ersten Gebots, K.35 (12.3.1767 Palace of the Archbishop, Salzburg) (part I of a 3-part sacred Singspiel)
La Betulia liberata, K.118 (K.74c) (oratorio) (1771)
Semiramis, K.App.11 (K.315e) (melodrama) (1779;) [lost]
Thamos, König in Ägypten, K.345 (K.336a) (incidental music) (1779? Salzburg)
P.D. La negrita y la cursiva son mías