Maling has won 11 caps for the All Blacks after making his debut in June 2002, with his last Test appearance being this summer against South Africa in the Tri-Nations match in Johannesburg.
"We have made no secret of the fact that we have been looking to supplement our resources in the second row for some time now," said Quins boss Mark Evans.
"Simon is an excellent lineout specialist and brings a wealth of experience with him into the squad.
"I have every confidence that he will help to get our season back on track after the disappointing start we have made. His arrival coincides with some very important matches for us in the Zurich Premiership during November."
Maling will remain with Quins until the end of the European season. He then heads to Japan after agreeing a three-year deal with Suntory.
Maling, who signed after the deadline for European registration, will not be available to help Quins in their efforts to progress from Pool 6.