Born at Rovereto in the Austrian Tyrol, he belonged to a noble and wealthy family. At an early age decided to enter the priesthood. After studying at Pavia and Padua, he was ordained priest in 1821.

In 1848 Rosmini was invited to serve in the Roman Curia of Pius IX as prime minister of the Papal States. He participated in the intellectual struggle which had for its object emancipation from Austria, but as a trusted ecclesiastical advisor and diplomat he was not an initiator of the movement which ended in the freedom and unity of Italy. In fact, while eager for the deliverance of Italy from Austria, his aim was to bring about a confederation of the states of the country, which was to be under the control of the pope. However upon establishment of the Roman Republic, the Pontiff was forced to flee and became estranged from his former advisor in political matters. The tenuous political circumstances made it very difficult to reconcile the two men's differing projects: innovative social and juridical reforms, however modest, fell victim to the more pressing existential needs of defending the supremacy of the Church's temporal powers.

Rosmini's works, Of the five wounds of the Holy Church and The Constitution of Social Justice, aroused great opposition, especially among the Jesuits, and in 1849 they were placed upon the Index. Rosmini at once declared his submission and retired to Stresa on Lago Maggiore, where he died. Before his death he had the satisfaction of learning that the works in question were dismissed, that is, proclaimed free from censure by the Congregation of the Index. Twenty years later, the word dismissed (dimittantur) became the subject of controversy, some maintaining that it amounted to a direct approval, others that it was purely negative and did not imply that the books were free from error. The controversy continued until 1887, when Leo XIII finally condemned forty of his propositions and forbade their being taught.

The English translation of Rosmini's works is being edited in Durham, UK.

The most comprehensive view of Rosmini's philosophical standpoint is to be found in his Sistema filosofico, in which he set forth the conception of a complete encyclopaedia of the humanely knowable, synthetically conjoined, according to the order of ideas, in a perfectly harmonious whole. Contemplating the position of recent philosophy from Locke to Hegel, and having his eye directed to the ancient and fundamental problem of the origin, truth and certainty of our ideas, he wrote: "If philosophy is to be restored to love and respect, I think it will be necessary, in part, to return to the teachings of the ancients, and in part to give those teachings the benefit of modern methods". He examined and analysed the fact of human knowledge, and obtained the following results:

1. that the notion or idea of being or existence in general enters into, and is presupposed by, all our acquired cognitions, so that, without it, they would be impossible;
2. that this idea is essentially objective, inasmuch as what is seen in it is as distinct from and opposed to the mind that sees it as the light is from the eye that looks at it;
3. that it is essentially true, because being and truth are convertible terms, and because in the vision of it the mind cannot err, since error could only be committed by a judgment, and here there is no judgment, but a pure intuition affirming nothing and denying nothing;
4. that by the application of this essentially objective and true idea the human being intellectually perceives, first, the animal body individually conjoined with him, and then, on occasion of the sensations produced in him not by himself, the causes of those sensations, that is, from the action felt he perceives and affirms an agent, a being, and therefore a true thing, that acts on him, and he thus gets at the external world, these are the true primitive judgments, containing
   1. the subsistence of the particular being (subject), and
   2. its essence or species as determined by the quality of the action felt from it (predicate);
5. that reflection, by separating the essence or species from the subsistence, obtains the full specific idea (universalization), and then from this, by leaving aside some of its elements, the abstract specific idea (abstraction);
6. that the mind, having reached this stage of development, can proceed to further and further abstracts, including the first principles of reasoning, the principles of the several sciences, complex ideas, groups of ideas, and so on without end;
7. finally, that the same most universal idea of being, this generator and formal element of all acquired cognitions, cannot itself be acquired, but must be innate in us, implanted by God in our nature. Being, as naturally shining to our mind, must therefore be what men call the light of reason. Hence the name Rosmini gives it of ideal being; and this he laid down as the fundamental principle of all philosophy and the supreme criterion of truth and certainty. This he believed to be the teaching of St Augustine, as well as of St Thomas, of whom he was an ardent admirer and defender.

In 1828 he founded a new religious community, the Institute of Charity, known generally since as the Rosminians. The members might be priests or laymen, who devoted themselves to preaching, the education of youth, and works of universal charity — material, spiritual and intellectual. They work in Italy, England, Ireland, France, Wales, New Zealand, Kenya, Tanzania, India, Venezuela, and America. In London they are attached to the historical Church of St Etheldreda, Ely Place, Holborn. In 1962, Rosmini College School for Boys was founded in Auckland, New Zealand, by Father Catcheside.

On 26 June 2006, Pope Benedict XVI signed a Decree of the heroic virtues, and hence declared Rosmini to be Venerable. On 3 June 2007, Pope Benedict XVI authorized the promulgation of a decree approving Rosmini's beatification. On November 18, 2007, he was beatified in Novara, Italy.