Ibrahim Halawa, 21, the son of Ireland's most senior Muslim cleric, was arrested during anti-government protests in Cairo in August 2013.
A cross-party group of TDs met Ibrahim Halawa in prison in Egypt.
The delegation was led by the Dail Speaker (ceann comhairle) Seán Ó Fearghaíl.
Speaking to RTÉ News from Egypt, Mr Ó Fearghaíl said Mr Halawa "looked healthy and was in very good spirits despite being deeply frustrated" by his situation.
He said the 21-year-old made repeated requests to be allowed to return home.
Mr Halawa told the TDs about a hunger strike that he has been on intermittently. The delegation asked him to refrain from the strike and look after his health.
On Wednesday, the TDs will meet with the Egyptian president and the speaker of the parliament.
Mr Halawa has been charged, along with 463 others, with inciting violence, rioting and sabotage.
His trial has been postponed 17 times.
The Irish government has been lobbying for Mr Halawa's release and deportation to Ireland.
His family has denied claims that Mr Halawa is a member of the Muslim Brotherhood, Egypt's oldest and largest Islamist organisation.
The Egyptian government has declared it a terrorist group, a claim the organisation rejects.
The speaker of the Irish parliament has said a Dublin man held in prison in Egypt is in "very good spirits", but is frustrated by his situation.