In 1857 he returned to Ireland and entered Trinity College Dublin, graduating with a BA in 1861; the same year was called to the Irish Bar.

He made a most effective speech on the reform bill brought in by James Service in 1880, but during the following stormy years there was little opportunity for a man of Wrixon's moderate views to become prominent.

In February 1886, however, when the Gillies ministry was formed, he was given the portfolio of Attorney-General and showed great ability in piloting bills through the house.

Wrixon showed sincerity, tactfulness, good judgment and persuasiveness in dealing with opposition, and was always ready to accept amendments which would improve bills.

In 1890 Wrixon went to London to represent the Victorian government in the Ah Toy case, which turned on the power of the colonies to refuse to admit aliens.