The 18 year old winger bolsters Southampton's attacking options following Lucy Watson's return to parent club Chelsea.
After coming through the ranks at Arsenal, Dennis has already experienced two years of senior football with time spent at Watford and Crystal Palace.
The youngster earned consecutive promotions in that time, first with Watford in the National League and then Crystal Palace in the Barclays Women’s Championship last season.
She then earned a move to Spurs in the summer of 2024 and made her senior debut for them in the Women’s League Cup, scoring her first goal in the competition in December.
Ahead of another spell of experience out on loan, Dennis said "I’m really excited to be here and get some minutes in for the rest of the season.”
"It’s been really good (moving to Spurs), being around the girls for the past couple of months and learning off of them every day, they’re all experienced players. Hopefully all the learning I’ve taken I can bring here.”
Remi Allen said: “We’re delighted to add Araya to the group; she's already gained experience at this level despite her young age and will bring some extra energy to us.
“She’s been in promoted squads before and learnt a lot as part of a WSL side this season, which we hope will help her hit the ground running for the rest of the year.”