San Giovanni Battista degli Spinelli was a 17th century confraternity church that used to be just outside the wall of Vatican City, just north of its northernmost point at the north-west corner of the junction of Viale dei Bastioni di Michelangelo with Via Sebastiano Veniero. This is in the Trionfale quarter.
The dedication was to St John the Baptist.
The church was built in 1617 by Rutilio Brandi, a Florentine glove-maker who was a disciple of St Philip Neri. The dedication to St John the Baptist was chosen because, as St John was alone in the wilderness, so this church was alone in the countryside back then.
Previous to the suburban development of this area after 1870, there was only a scattering of individual houses in the vineyards of this area, which this very small church served. It was the responsibility of the Chapter of St Peter's, and was run by the Confraternita del Rosario a Monte Mario. The Rosary connection survived in the area after the church was demolished, at Santa Maria del Rosario in Prati.
It was demolished in 1849, during the conflict occasioned by the Roman Republic of that year.
It was in what is now Via Leone IV, just north of the bastion on the corner of the Vatican City walls. The entrance to number 2, on the west hand side, marks the site. The address is of the convent of the Immacolata dei Miracoli.
The church was small, with a long and narrow plan which was a parallelogram angled to the right. There was a square presbyterium separated from the nave by a triumphal arch.
The façade was very straightforward. The entrance was protected by a raised floating cornice, and above this was a large square window with a wide raised Baroque frame. Above this in turn was a small fresco of St John the Baptist, in the gable. A pair of smaller windows, also with wide raised frames but plain in design, flanked the door.