From Longman Dictionary of Contemporary Englishit’s a good thing (that)it’s a good thing (that)LUCKY spoken used to say that it is lucky or good that something has happened It’s a good thing we brought some food with us. → thing
Examples from the Corpus
it’s a good thing (that)• But it's a good thing it happened now..• I decide it's a good thing that I don't see Sean try to capture Ian's incandescent dance.• So it's a good thing to get one's mind off in one's spare time.• Still, it's a good thing from the hunt's point of view that new blood is coming along, surely?• I think it's a good thing. 