However, in comments reported by Football London, the Spurs' boss also said he doesn't have any control over transfer decisions.
Walker-Peters has spent the second half of the season out on-loan with Saints where he has featured five times in the Premier League.
Having initially linked up with Ralph Hassenhutl's side in January that cast doubt over his Spurs future having only played a part in three Premier League games for the North London club.
Having failed to break into both Mauricio Pochettino's side and Mourinho's a loan move was the perfect chance to prove his worth in England's top-flight.
Following the right-backs impressive performance, along with the rest of Southampton's squad, in their 1-0 victory over Manchester City, last weekend Walker-Peters certainly caught people's eye.
Leaving the door open for a return to his parent club as Mourinho said: "We let him go because we think he has the right to be happy. He’s happy now I think. He’s playing and playing well. I’m not in control of the transfer decisions but the general feeling is there’s a place for him here."
Mourinho won't stand in his way
However, the Tottenham boss also admitted if Walker-Peters is happy and wishes to remain on the South Coast then the Portuguese manager won't stand in his way.
He said: “But if his desire is to leave the club in search of happiness I don’t think we’d stop him. He’s a player with a good value in the market but I don’t think we’d stop him doing it."
With the summer transfer now opening the decision has been left with the 23-year-old on whether he wishes to remain down South or return to the capital.
That is of course if Hassenhutl's side does approach Spurs to discuss a permanent transfer - which seems likely considering his recent impressive, defensive performances and their ample cover in Walker-Peter's position.