Uinseann Ó Rathaille MacEoin (4 July 1920 – 21 December 2007) was an Irish architect, journalist, republican campaigner and historian.

In the decades after his internment, MacEoin would emerge as an influential architect who became involved with the preservation of historic sections of Dublin's inner city.

Uinseann Ó Rathaille MacEoin was born Vincent O'Rahilly McGuone in Pomeroy, County Tyrone on 4 July 1920.

[2] MacEoin attended boarding school at Blackrock College, and was then articled to the architectural practice of Vincent Kelly in Merrion Square.

MacEoin wrote a large proportion of the copy in these periodicals, much under his own name, but he also used pseudonyms, in particular in Plan as "Michael O'Brien".

He wrote about his strong views on social housing, national infrastructure, and foreign and slum landlords, often libellously.

Along with fellow campaigners, Mariga Guinness and Deirdre Kelly, this demonstrated that these buildings could be salvaged and were not the dangerous structures other architects and developers claimed them to be.

MacEoin also bought and saved Heath House, near Portlaoise, County Laois, living there towards the end of his life.

He offered free conservation and architectural advise to community groups, and was a volunteer on the renovation works on projects including Tailors Hall.

[1] He remained politically active, joining Clann na Poblachta, the Wolfe Tone Society, the Dublin Civic Group, the Northern Ireland Civil Rights Association and the Irish Anti-Apartheid Movement.

MacEoin testified that in February 1962 he had travelled with £50,000 in cash from Dublin to lodge to Docherty's account in the Royal Bank of Scotland in Belfast, as a loan.

MacEoin was placed in police custody for the day, and eventually he agreed to give the name in writing in confidence to the Judge.

The Judge ultimately ruled that Docherty was guilty of attempted fraud and perjury and that MacEoin's involvement reeked of criminality.

[1] In Sinn Féin's 1971 Éire Nua social and economic programme, MacEoin wrote the chapter on 'Planning', and attended meetings in Monaghan in the early 1970s on the Dáil Uladh, a parliament for the 9-county Ulster.

[1] As an environmentalist, MacEoin opposed private car ownership, and advocated for cycleways and the redevelopment of the railway lines.