The Glasgow businessman replaced former Home Secretary John Reid who stood down after four years in the post.
Afterwards, as he met the media in the Celtic boardroom, Bankier said: "I feel quite emotional and incredibly humble.
"It is really impacting on me, the incredible lifetime privilege to take over the helm of an institution like this.
"Humble, that's the word. That's a bit of a cliche but that's how I feel.
"I've grown up with Celtic all my life but it is when you put this suit and tie on and face people, it really hits home to you what it's all about.
"I need to get my feet under the table and then get a good working relationship with the man on my left (chief executive Peter Lawwell).
"But what I bring is 35 years of my career.
"I have been in law, finance, public companies and private companies, big situations and small situations and so I will bring fresh thinking to every aspect of what we are doing."
Bankier turned the clock back almost 50 years to reveal his Celtic credentials.
"I will tell you a story," he said.
"I went to St Aloysius primary school and in primary six we had a teacher who was a Celtic nut.
"And every time Celtic won we got no homework but every time Celtic lost we got double homework.
"This was season 1962/63 and Celtic had a dreadful season.
"They lost three times to Rangers and drew once. The goalkeeper was Frank Haffey.
"And Frank Haffey doesn't know this, but he contributed massively to my education because we got so much homework at that time.
"So that is where it all began for me and I went on to the Lisbon Lions.
"But I lay it on the table, I have not been a season ticket holder for Celtic, the reason for that is that I travelled a lot.
"As a lawyer I was working in London a lot and when I was in whisky I was around the world, so I didn't find time to commit to that sort of routine.
"It was a lifestyle thing, nothing to do with interest and passion for the club.
"Anywhere I was, I was tuning in to what was going on."