The minister for home affairs in the governments of Andrew Fisher and Bill Hughes in the early 1900s, King O'Malley also oversaw a ban on the granting of new liquor licences in the ACT between 1910 and 1928.

So, a little perversely, one of Canberra's favourite pubs is called King O'Malley's.

Owner Peter Barclay said the new portrait was about honouring the pub's traditions but putting a modern edge on them.

The colourful portrait of O'Malley was done by artist Christopher Toth, the man who also created the stunning mural of the late suits salesman, John Hanna.

"I was really impressed with John Hanna's portrait," Peter said.

"I gave Christopher a lot of literature about King O'Malley and he was genuinely interested in it.

"I told him I had no preconceived ideas for the portrait, just to go for it. And he's come up with something really different."

The portrait was unveiled on Monday, Canberra Day, the pub also the location of a five-year reunion for the team who helped to organise the centenary of Canberra in 2013.

(We were told the centenary's creative director Robyn Archer was invited but had something else on.)

And it's just the start of a busy week for King O'Malley's.

It is hosting an event on Friday for the Leukaemia Foundation's World's Greatest Shave. Professional hairdressers will on site from 4pm to 7pm to shave ($10) or colour your hair ($5), with all proceeds to the foundation.

Why not go for a brilliant shade of green, with King O'Malley's also celebrating St Patrick's Day on Saturday.

St Pat's festivities starts with a barbecue at 8am on Saturday and going into the "wee hours of the morning", according to Peter. The Gecko Gang will be there during the day for the kids and there will also be lots of live Irish entertainment and music.

And if that wasn't enough, a new mural of the famous Guinness Toucan is being officially unveiled at the back of King O'Malley's in Bible Lane, Civic, on St Patrick's Day, as part of the effort to liven up the city's laneways.