The Germany playmaker completed a late switch to the Emirates Stadium on deadline day from Real Madrid, becoming Arsenal's fourth signing of the window following Yaya Sanogo, Mathieu Flamini and Emiliano Viviano.
And with the prolific German netting nine goals in 32 league appearances last season, as well as laying on a further 16 for his team-mates, Walcott believes Ozil will boost the team after a mixed start to the new campaign.
Arsene Wenger's side lost their opening game of the season at home to Aston Villa, but have since recovered - comfortably progressing past Fenerbahce in the UEFA Champions league and winning Sunday's north London derby, 1-0 against Tottenham.
"It definitely shows a statement that we are ready to step up," Walcott said.
"We had a disappointing start to the season, but we have bounced back and it is looking fantastic now.
"With the likes of Ozil joining the club, it is only going to boost everyone."
Ozil is likely to be in line for his Arsenal debut when they travel to Sunderland on August 14.
