In the 31st Dáil, Farrell was a member of the Joint Oireachtas Committee on Justice, Equality and Defence and the Joint Oireachtas Committee on Finance, Public Expenditure and Reform. He was also the chairperson of the Fine Gael Committee on Public Expenditure and Reform from 2011 to 2013 and the Fine Gael Committee on Justice, Defense and Equality from 2013 to 2016. Farrell was the subject of controversy after he hired his wife, Emma Doyle, as his temporary parliamentary assistant for four months in the Dáil. This was just two weeks after she was rejected by Farrell's Malahide Fine Gael Party branch as his replacement on Fingal County Council in 2011. Parliamentary assistants salaries range between €41,092 and €52,200 per year, which is paid for by the State. In 2013, Farrell was appointed Head of the Irish Delegation to the OSCE Parliamentary Assembly by TaoiseachEnda Kenny. In October 2013, he referred to singer Sinéad O'Connor as being "mad as a brush", in a tweet. He later issued a brief apology via his website and later deleted the apology.
Farrell took Hertz Rent A Car to court after one of its vehicles knocked against his Audi A6 while its driver was engaged in an encounter with a spider which crawled along her arm at a traffic stop. Farrell claimed to have experienced neck and shoulder injuries as a result of the collision, which occurred in Drumcondra on 9 April 2015. In 2018, a photograph - showing Farrell at the time he was supposed to have been injured holding a poster of himself on an electricity pole while standing on a ladder in Skerries - was shown in Dublin District Court. Judge Michael Coghlan looked unfavourably on the personal injuries claim, ruling that Farrell had not sustained a "significant injury" and awarding him a total of €2,500. Judge Coghlan also noted in court that a separate claim by Farrell for material damage to his car had been relinquished since the accident. Photographs taken by the driver at the scene were shown to the court and some difficulty was had in locating the precise damage to Farrell's motor car. The Sunday Independent suggested the case "raises serious questions about Mr Farrell's judgment", contrasting it with insurance problems for motorists and referring to past remarks made by Farrell on Ireland's supposed "compo culture". In November 2018, Farrell spoke publicly about his lifelong battle against insomnia, which often keeps him awake until 4 am. Farrell's insomnia first occurred, he has said, when he was "five or six".
