More of a loosehead, but also adept at tighthead, the prop has signed a three-year deal with the Exiles after eight seasons in Ireland.
And the 33-year-old, who came off the bench for the Lions in their midweek clash with the Melbourne Rebels this summer, admits he is excited about his new challenge in London, not that his focus has shifted from the job in hand with Ulster this season.
"I have enjoyed eight fantastic seasons at Ulster and will leave the club with many happy memories," said Court.
"London Irish is a new challenge and one I am looking forward to. There is still a lot of work to do for the remainder of this season at Ulster and that will be my immediate focus."