He was educated at Galway College, and after five years spent in America he arrived in Victoria in 1855, where he joined Angus Mackay in the purchase of the Bendigo Advertiser, and afterwards started the McIvor Times and Riverine Herald.

From July 1868 to September 1869 he was Minister of Justice in the second James McCulloch Administration, exchanging this office for that of Solicitor-General about a fortnight before the defeat of the Government.

Whilst at the head of the Lands Office Casey reorganised the department, and constituted the survey branch on an effective basis.

[3] Though still claiming to be a Liberal, Casey assumed an independent attitude towards the second Graham Berry Ministry from 1877 to 1880, and was in consequence ejected from his seat at Mandurang at the general election in the latter year.

Casey, who was the first President of the Federal Bank of Australia, was executive vice-president of the Melbourne International Exhibition (1880), and in that capacity, and as chairman of the Great Britain Committee, contributed much to its success.