The Rangers boss believes the midfielder, who has 50 caps for Wales, will add experience to his side.
He said: “It is more positive news. The opportunity came up to get Andy King in the last 48 hours and I jumped at the chance for numerous reasons.
“Over the course of the last 14 months I have been trying to build a squad but a lot of players are inexperienced and young and they need guidance and leadership in the dressing room so it was a no brainer and financially as well it makes total sense.”
Gerrard says the 30-year-old is ready to come to Ibrox and fight for his place in the team.
He added: “I think he can do numerous jobs in the middle of the pitch. He can play as a Steven Davis for example and control a game with his passing. I think he can go box-to-box and he can play either side of a holder, left or right.
“He got an injury last year which frustrated him a lot so when I spoke to him this evening he was very hungry to come and compete and fight for his place.
King is Leicester’s all-time top scoring midfielder and has played over 375 times for the club.
Gerrard added: “We thank Leicester for the opportunity because I think you know and I know from a financial situation there is no way in the world we can bring Premier League players in but when this opportunity came up I wanted to get it done quick because it was a fantastic offer we had to grab it and it made total sense in every way shape and form.”