Onlookers applauded as some 200 soldiers from the Regiment's First Battalion, led by the band, pipes and drums, staged the parade just weeks after returning from Iraq.
Affiliated Army cadets and members of the Irish Guards Association joined the troops to help reinforce their links with the city that is European Capital of Culture 2008.
Lieutenant Colonel Michael O'Dwyer MBE, Commanding Officer 1st Battalion Irish Guards (1 IG), said:
"It is a great honour for the Irish Guards to exercise our freedom of Liverpool in this historic and memorable year for Liverpool. It is made all the more special because of the tremendous support given to the battalion from the people of Liverpool during our tour in Iraq. This is an ideal way for us to say thank you."
Veterans Minister Derek Twigg was on hand as Major General Sir Sebastian Roberts, of the Irish Guards, unveiled a memorial for fallen comrades, a tablet stone, on behalf of the association at St John's Gardens in the city centre.
Earlier in the day a service of thanksgiving was held at the city's Anglican cathedral before the parade made its way through the city centre to St George's Hall.
Among those taking part in the parade were Liverpool brothers Michael (Mick), James and Peter Hogan, who all serve in 1 IG. At 37 years old, Michael, a Warrant Officer Class Two (WO2), is the eldest and has been a soldier for 20 years. James, 32, is a Lance Corporal with ten years under his belt, and 26-year-old Peter, is also a Lance Corporal, but with nine years' service. All three served with the Battalion in Iraq in 2003 and 2007.
WO2 Mick Hogan explained how proud he was to be part of the parade in Liverpool when the regiment was granted its 'Freedom' in 2000:
"It was an outstanding day. It was just a great honour. My parents came down to see us and they were so proud. Me, Peter and James served in Iraq in 2003 and then again last year. It is quite worrying for me because of the job I do. I work in signals in the battalion.
"Every time there's an incident on the ground, and they all get back to us via the signals, I would be conscious that it could be one of my brothers. But at the same time it's a huge bonus to have them with you.
"We all get on really well and it's good to be able to talk to them. We would all be in different locations, but there would be times when we'd meet up in the COB [the main military operating base in Basra] for a chat – we'd just slag each other off really and take the mick about our football teams! Me and Peter are Blues, but James is a Red! My parents are extremely proud of all of us and everything we have done. They do get worried, but they are also really proud of us."
Irishmen and women flocked to Liverpool to escape the famine caused by the potato blight in Ireland in 1837. On 1 April 1900, under Queen Victoria's direction, Army Order 77 came into effect, raising the Irish Guards. This commemorated the bravery and spirit shown by the 'Fighting Irish' during the South African War.
Many recruits enlisted in Liverpool and the Irish Guards have maintained a link with the city ever since. On 1 April 2000, on the centenary of the regiment, the city of Liverpool honoured the Irish Guards in bestowing the freedom of Liverpool.
