Walcott has been in good form of late, scoring four goals in his last four appearances for Arsenal.
Injuries to Adam Lallana and Raheem Sterling have further increased the 27-year-old’s chances of being involved, and Southgate believes that he is worthy of a return to the international fold.
“I’ve been told I have to bring someone (to the press conference) who will start so, yes, Theo will start,” he told reporters.
“It’s a good moment for him. He’s in superb form for his club and as an international manager your ideal is to have people in the squad who are playing well.
“He’s maturing hugely as a player and he should feel full of confidence because everything I’ve seen suggests he’s going to continue that.”
Walcott, who was not part of England’s Euro 2016 squad, will win his 45th international cap against Malta.