Irvine has enjoyed success as an assistant manager but was a shock choice for Albion who also interviewed sacked Spurs boss Tim Sherwood.
Irvine is desperate to make a good impression to the Baggies fans and wants to add players to his squad as soon as possible, with the academy playing a major role.
“I’m absolutely delighted to get the job,” said Irvine.
“I’ve got a great deal of respect for the club right the way from the first team through to the Academy.
“The situation at this club is similar to what I went through at Everton when I went there with David.
“It is run very sensibly and, as a result of that, any head coach coming in has got a great chance of doing a good job.
“A number of the players who have had success in the Premier League with the club are still here.
“But it’s a small squad at this moment in time and, clearly, the first job is going to have to be to get some more players in.
“My passion is for coaching and I believe my strength is on the training ground, which is where we need to get the work done.”