Giambattista was born in Madrid, Spain, the fourth of the twelve children of Luca Spinola and Battina Lomellini. They were immigrants from Genoa in Italy, members of the influential Spinola family of that city, which had long been active in Genoese politics. He was the nephew of Cardinal Giandomenico Spinola. During his career, he participated in three papal conclaves.
Spinola studied law as a young man, receiving doctorates in both civil and canon law. At an unknown date he entered Church service. In 1648 he was appointed as archbishop of the Roman Catholic Archdiocese of Acerenza and Matera, while still a deacon. He became the Archbishop of Genoa in 1664. Additionally he was named as Secretary for the Sacred Congregation of Bishops and Regulars by Pope Clement X, as well as Governor of Rome and Vice Camerlengo of the Sacred College of Cardinals, retaining the Secretariat of the Sacred Congregation from 26 October 1675 until 1 September 1681. He was forced to resign as Archbishop of Genoa on 16 March 1681 for reasons of health. He served as pro-Governor until 28 July 1691.
Shortly after his resignation, Spinola was named a Cardinal Priest by Pope Innocent XI, with his titular church that of Santa Cecilia in Trastevere in Rome. He served briefly in the position of Camerlengo, from January 1691 to March 1692, again resigning for reasons of health. In 1696 he had his titular church changed to the Basilica of Sant'Agnese fuori le mura in Rome, a title he held until it was again changed, this time to that of the Church of Santa Maria in Trastevere in 1698.
Spinola died in his palace in Rome on 4 January 1704. His body was laid out in the Church of San Lorenzo in Lucina, with his burial taking place on 7 March 1704 at the Church of San Salvatore alle Coppelle, in front of the main altar.
- "Giambattista Cardinal Spínola (Sr.)". Catholic Hierarchy. Retrieved 2 January 2012.
- "Consistory of September 1, 1681". Cardinals of the Holy Roman Church. Retrieved 2 January 2012.
- Cardinal Title S. Cecilia Giga Catholic Information
- Cardinal Title S. Agnese fuori le mura Giga Catholic Information
- Cardinal Title S. Maria in Trastevere GCatholic