Gonzaga was born the eldest of seven children, at his family's castle in Castiglione delle Stiviere, between Brescia and Mantua in northern Italy in what was then part of the Duchy of Mantua, into the illustrious House of Gonzaga. "
Aloysius" is the Latin form of Aloysius de Gonzaga's given name in Italian, Luigi.
He was the son of Ferrante de Gonzaga (1544–1586), Marquis of Castiglione, and Marta Tana di Santena, daughter of a baron of the Piedmontese Della Rovere family.
 His mother was a lady-in-waiting to Isabel, the wife of Philip II of Spain.

As the first-born son, he was in line to inherit his father's title and status of Marquis.
His father assumed that Aloysius would become a soldier, as that was the norm for sons of the aristocracy and the family was often involved in the minor wars of the period.
His military training started at an early age, but he also received an education in languages and the arts.
As early as age four, Luigi was given a set of miniature guns and accompanied his father on training expeditions so that the boy might learn "the art of arms".
At age five, Aloysius was sent to a military camp to get started on his training.
His father was pleased to see his son marching around camp at the head of a platoon of soldiers.
His mother and his tutor were less pleased with the vocabulary he picked up there.

He grew up amid the violence and brutality of Renaissance Italy and witnessed the murder of two of his brothers.
In 1576, at age 8, he was sent to Florence along with his younger brother, Rodolfo, to serve at the court of the Grand Duke Francesco I de' Medici and to receive further education.
 While there, he fell ill with a disease of the kidneys, which troubled him throughout his life.
While he was ill, he took the opportunity to read about the saints and to spend much of his time in prayer.
He is said to have taken a private vow of chastity at age 9.
In November 1579, the brothers were sent to the Duke of Mantua.
Aloysius was shocked by the violent and frivolous lifestyle he encountered there.

Aloysius returned to Castiglione where he met Cardinal Charles Borromeo, and from him received First Communion on 22 July 1580.
After reading a book about Jesuit missionaries in India, Aloysius felt strongly that he wanted to become a missionary.
 He started practicing by teaching catechism classes to young boys in Castiglione in the summers.
He also repeatedly visited the houses of the Capuchin friars and the Barnabites located in Casale Monferrato, the capital of the Gonzaga-ruled Duchy of Montferrat where the family spent the winter.
He also adopted an ascetic lifestyle.

The family was called to Spain in 1581 to assist the Holy Roman Empress Maria of Austria.
They arrived in Madrid in March 1582, where Aloysius and Rodolfo became pages for the young Infante Diego.
Aloysius started thinking in earnest about joining a religious order.
He had considered joining the Capuchins, but he had a Jesuit confessor in Madrid and decided instead to join that order.
His mother agreed to his request, but his father was furious and prevented him from doing so.

In July 1584, a year and a half after the Infante's death, the family returned to Italy.
Aloysius still wanted to become a priest, but several members of his family worked hard to persuade him to change his mind.
When they realized there was no way to make him give up his plan, they tried to persuade him to become a secular priest and offered to arrange for a bishopric for him.
If he were to become a Jesuit he would renounce any right to his inheritance or status in society.
His family's attempts to dissuade him failed; Aloysius was not interested in higher office and still wanted to become a missionary.
Gonzaga was born the eldest of seven children, at his family's castle in Castiglione delle Stiviere, between Brescia and Mantua in northern Italy in what was then part of the Duchy of Mantua, into the illustrious House of Gonzaga. "Aloysius" is the Latin form of Aloysius de Gonzaga's given name in Italian, Luigi. He was the son of Ferrante de Gonzaga (1544–1586), Marquis of Castiglione, and Marta Tana di Santena, daughter of a baron of the Piedmontese Della Rovere family.  His mother was a lady-in-waiting to Isabel, the wife of Philip II of Spain.
As the first-born son, he was in line to inherit his father's title and status of Marquis. His father assumed that Aloysius would become a soldier, as that was the norm for sons of the aristocracy and the family was often involved in the minor wars of the period. His military training started at an early age, but he also received an education in languages and the arts. As early as age four, Luigi was given a set of miniature guns and accompanied his father on training expeditions so that the boy might learn "the art of arms". At age five, Aloysius was sent to a military camp to get started on his training. His father was pleased to see his son marching around camp at the head of a platoon of soldiers. His mother and his tutor were less pleased with the vocabulary he picked up there.
He grew up amid the violence and brutality of Renaissance Italy and witnessed the murder of two of his brothers. In 1576, at age 8, he was sent to Florence along with his younger brother, Rodolfo, to serve at the court of the Grand Duke Francesco I de' Medici and to receive further education.  While there, he fell ill with a disease of the kidneys, which troubled him throughout his life. While he was ill, he took the opportunity to read about the saints and to spend much of his time in prayer. He is said to have taken a private vow of chastity at age 9. In November 1579, the brothers were sent to the Duke of Mantua. Aloysius was shocked by the violent and frivolous lifestyle he encountered there.
Aloysius returned to Castiglione where he met Cardinal Charles Borromeo, and from him received First Communion on 22 July 1580. After reading a book about Jesuit missionaries in India, Aloysius felt strongly that he wanted to become a missionary.  He started practicing by teaching catechism classes to young boys in Castiglione in the summers. He also repeatedly visited the houses of the Capuchin friars and the Barnabites located in Casale Monferrato, the capital of the Gonzaga-ruled Duchy of Montferrat where the family spent the winter. He also adopted an ascetic lifestyle.
The family was called to Spain in 1581 to assist the Holy Roman Empress Maria of Austria. They arrived in Madrid in March 1582, where Aloysius and Rodolfo became pages for the young Infante Diego. Aloysius started thinking in earnest about joining a religious order. He had considered joining the Capuchins, but he had a Jesuit confessor in Madrid and decided instead to join that order. His mother agreed to his request, but his father was furious and prevented him from doing so.
In July 1584, a year and a half after the Infante's death, the family returned to Italy. Aloysius still wanted to become a priest, but several members of his family worked hard to persuade him to change his mind. When they realized there was no way to make him give up his plan, they tried to persuade him to become a secular priest and offered to arrange for a bishopric for him. If he were to become a Jesuit he would renounce any right to his inheritance or status in society. His family's attempts to dissuade him failed; Aloysius was not interested in higher office and still wanted to become a missionary.
Aloysius Gonzaga