A product of Southampton's successful academy, the utility full back is capable of operating further forward and will add needed depth to Boro.
Middlesbrough's official website reports the deal as a season long loan, and are excited about the recruitment of an England under-21 international.
With over 50 appearances for the south coast side, McQueen has played in both the Premier, and Europa League.
With two other loan deals this season — Jordan Hugill and the returning Mo Besic — the north east club have brought in some experienced top division talent, and have their fingers crossed that they can help achieve supporters dreams.
Many fans are unfamiliar with McQueen's skill set, but are willing to give him a go due to the fact he has come through such a prestigious youth set up.
Currently sitting 2nd in the Championship after a perfect start, Middlesbrough are yet to concede a goal. Whether Pulis has ideas to start McQueen further up the pitch is to been seen, but at this current juncture, he may have a hard time breaking through defensively.