The 18-year-old was included in England manager Roy Hodgson's 23-strong squad for next month's European Championships after impressing during his debut season at Arsenal.
Oxlade-Chamberlain joined the London club from Championship side Southampton last summer, and his inclusion in Hodgson's plans is the culmination of a season which saw him put himself on the map in both the Premier League and Champions League.
"I'm obviously delighted," Oxlade-Chamberlain told Arsenal.com. "To be picked for your country at any stage is a massive honour and to be at a huge tournament likes the Euros is such a bonus.
"I would have probably laughed if someone had told me I would be in the Euro 2012 a year ago.
"Obviously you would like to think that and it is what you aim towards but sometimes you have to be realistic and realise it might take a little bit longer than that."