He was the second son of King Victor Amadeus III of Sardinia and Maria Antonietta of Spain, daughter of King Philip V of Spain and Elisabeth Farnese. Victor Emmanuel was known from birth as the Duke of Aosta. From 1792 to 1796, Aosta's father had taken an active part in the struggle of the old powers against the French Revolutionary forces, but were defeated and forced to make peace in 1796. The old king died shortly thereafter, and his eldest son and successor, Charles Emmanuel IV was faced in December 1798 with a French occupation and, eventually, annexation, of his mainland territories.

Charles Emmanuel and his family were forced to withdraw to Sardinia, which was the only part of his domains not conquered by the French. Charles Emmanuel himself took little interest in the rule of Sardinia, living with his wife on the mainland in Naples and Rome until his wife's death in 1802, which led the childless Charles Emmanuel to abdicate the throne in favor of his younger brother. Aosta took the throne on June 4, 1802 as Victor Emmanuel I. He ruled Sardinia from Cagliari for the next twelve years, during which time he constituted the Carabinieri a Gendarmerie corp, still existing as one of the main branches of the military of Italy.

Victor Emmanuel could return to Turin only in 1814, his realm reconstituted by the Congress of Vienna with the addition of the territories of the former Republic of Genoa. The latter became the seat of the Sardinian Navy. Victor Emmanuel abolished all the freedoms granted by the Napoleonic Codices and restored a fiercely oppressive rule: he refused any concession of a constitution, entrusted the instruction to the Church and reintroduced the persecutions against Jews and Waldensians.

After the death of his brother in 1819, he also became the Jacobite pretender to the British thrones (as Victor I), although he, like his brother, did not make any public claims to this effect. When Victor Emmanuel died, Lord Liverpool, the Prime Minister of the United Kingdom, wrote to his ministerial colleague George Canning that there should be public mourning in Britain, as a significant number of Britons had regarded Victor Emmanuel as their rightful king.

After the outbreak of the liberal revolution in his lands in 1821, he abdicated in favor of his brother, Charles Felix. Victor Emmanuel died in the Castle of Moncalieri. He is buried in the Basilica of Superga.

On 21 April 1789, he married Archduchess Maria Teresa of Austria - Este, daughter of Ferdinand, Duke of Modena (who was the son of Francis I, Holy Roman Emperor). They had six daughters and one son who died very young.