He completed a BA in English Literature and Philosophy at University College Cork and later attended the King's Inns.

[3] He is a former chair of the Incorporated Council for Law Reporting and became a bencher of the King's Inns in 2017.

He appeared for the State in a challenge taken by Brian Mohan to the constitutionality of parliamentary gender quota legislation and an action initiated by Jolyon Maugham to try to prevent Brexit through the High Court.

[10] His appointment arose out of a vacancy was created due to the retirement of Michael Peart.

[11] Collins was appointed to the Law Reform Commission as a part-time commissioner for a five-year term in October 2020.