Philip was born on 28th May 1856 at Lu Monferrato (Alessandria) and at twenty one years old he joined Don Bosco. When he was ordained priest his first responsibility was the formation of aspirants and novices. In 1889 Don Rua sent him to Spain as Rector of the community at Sarria. Later he was asked to be Provincial and made a decisive contribution to the development of the Salesians in Spain.

As Vicar General of the Congregation he displayed even more of his fatherly gifts and his willingness to take new initiatives: care of vocations, setting up centres for spiritual and social support of young workers, guide and support of the Daughters of Mary Help of Christians at an important stage of their history. He gave great encouragement to the Cooperators and founded the world Federation of Past Pupils. While working with the 'Zelatrici di Maria Ausiliatrice' he conceived and saw through a plan to set up a new form of consecrated life in the world, which would later grow into the Secular Institute of 'Volunteers of Don Bosco' (VDB).

He was elected Rector Major in 1922 and focussed his energy on adapting the spirit of Don Bosco to the current situation. Don Francesia wrote "Don Rinaldi was only missing the voice of Don Bosco: he had everything else!" He was a master of Salesian ways and spirituality and brought about a renewal in the interior life of Salesians, absolute confidence in God and unlimited trust in Mary Help of Christians. He asked Pope Pius XI for an indulgence for 'sanctified work'. He took great care of the missions and sent many young Salesians to learn languages and customs so that they could be more immersed in local culture and spread the gospel more effectively.

He died on 5th December 1931 and was beatified by Pope John Paul II on 29th April 1990. His remains are venerated in the crypt of the Basilica of Mary Help of Christians and his memory is celebrated on 5th December.