She has become the first serving head of government to address the chamber
The First Minister of Scotland Nicola Sturgeon has become the first serving head of government to address the Seanad.
It is part of her two-day visit to Dublin, which saw her meet President Michael D Higgins and visit Trinity College.
She was greeted with applause from Senators as she entered the chamber.
While the Seanad Cathaoirleach, Senator Denis O'Donovan, said this was "a historic occasion, which will strengthen and deepen the links between our two countries".
He also said the chamber wished her well "to secure the optimum outcome for the people of Scotland" during Brexit negotiations.
Beginning her speech, Ms Sturgeon compared Ireland and Scotland historic links, having seen the Book of Kells for the first time herself last night.
She then talked about how both countries are "repaying the obligations" by offering help to others.
"Much of the modern history of both Scotland and Ireland has been shaped by our experiences of emigration beyond these islands.
"As a result of that, for all the deep regret that we undoubtedly feel about the historic causes of emigration from our shores - both of our countries can today take great pride in what Scottish and Irish people have achieved overseas."
"Europe is now facing its greatest refugee crisis since the end of The Second World War - and Scotland and Ireland both know that in other times, and in very different circumstances, the people's of our nations were also driven by the instinct for self-preservation and the desire for a better life.
"Perhaps that helps to explain why both Scotland and Ireland have responded with such an open heart to the current crisis.
"For Scotland and Ireland to turn away from this crisis wouldn't simply be a failure of compassion, it would be a denial perhaps of our own identity.
"By helping people who so desperately need our help today, we are in some senses repaying the obligations of our past".
Ms Sturgeon also told the Seanad that she believes that relations between Scotland and Ireland are "stronger, warmer, and more harmonious than they have ever been in the past".
"I believe passionately that all of these ties will be strengthened even further to our mutual benefit in the years ahead.
"Of course throughout the last four decades, an important context for our cooperation has been our shared place in the European Union".
The Scottish First Minister then went on to talk bout the UK Brexit vote, suggesting the referendum result to leave "was deeply unwelcome".
"Brexit is the greatest foreign policy challenge Ireland has faced since it joined the European Union."
Hinting again at an independence referendum for Scotland, she told Senators: "If the path that the UK chooses to take turns out to be deeply damaging to Scotland's best interests...then the people of Scotland must have the right to choose a different future.
"Scotland's experiences in Europe have not, of course, been identical to Ireland - we are not an independent member state, yet", she told the chamber.
She also said the Scottish government wants the UK as a whole to seek continued membership of the EU single market and customs union.
Ms Sturgeon compared some measures that Ireland and Scotland have adopted after each other: the smoking ban, marriage equality and, now up for debate here, a ban on minimum unit alcohol pricing.
"Scotland and Ireland are living examples of the positive impact that small, open, outward looking countries can have on the world around us", she concluded to a standing ovation.