The 20-year-old England international spent 11 years with the English south-coast club before leaving for the Emirates Stadium in 2011 in a £12 million ($19.8 million, 14.5 million euros) move.
Oxlade-Chamberlain will return to St Mary’s for the second time on Tuesday and he is looking forward to facing a familiar foe.
“To go back there in any sense is always really nice, especially when we go to play them,” he said.
“Last season I went back there and it was a surreal feeling for me, warming up on the opposite side of the pitch and being in the opposite dressing room.
“It was the first time I went back there to play, so it was a bit weird for me. I’m looking forward to going back this season. Obviously they’re doing really well, so it’s a tough game for us.”
Oxlade-Chamberlain made his first start since suffering a knee injury in August as Arsenal beat third-tier Coventry City 4-0 in the FA Cup fourth round on Friday.
The winger has returned to a team high on confidence at the top of the Premier League table, having won their last seven matches in all competitions.
Oxlade-Chamberlain says a close bond between the players formed over the past few years is underpinning their success.
“The main group and the spine of the team has been together for two or three years, so it’s starting to form that togetherness,” he said.
“Knowing each other better on and off the pitch helps our style of play. We’ve learnt that everyone has been in and around it for a few years now and we know what the boss (Arsene Wenger) expects and how he wants us to go about it.
“We know what to expect with each other and I think you can see that now when we do play. Even when we’re not playing well, we know how to grind out results and that’s a big thing.
“We set each other high standards and if you do something that’s not good enough, you can bet your bottom dollar that one of your team-mates will tell you when he believes you’re better than that.”
Southampton enter the fixture unbeaten in their last four matches despite a fortnight of turbulence off the field.
The resignation of influential chief executive Nicola Cortese was followed by the suspension of record-signing Dani Osvaldo following a training-ground altercation with team-mate Jose Fonte.
However, the Saints made light of their troubles to ease past Championship club Yeovil Town in the FA Cup thanks to strikes from Guly Do Prado and 18-year-old forward Sam Gallagher — his first for the club.
Brazilian Do Prado’s goal, from the penalty spot, was his first since January 2012.
“I must say thank you to my team-mates for supporting me,” he said. “First of all, I asked Jay Rodriguez if I could take the penalty, but he said no.
“After a few minutes he changed his mind and gave the ball to me so I just want to thank him, and also Morgan Schneiderlin for helping me get the ball.
“We are all friends, so we don’t need to fight over a penalty. We help each other.
“We get confidence from these wins. We play for a win in every game, whether it’s in the FA Cup or the Premier League.
“The win will give us confidence for Tuesday night against Arsenal. Now we have to think about that because it’s going to be another big, hard game, but we are going to play to win.”