His mother is former actress Sharlene Martin, and his father is business exec. Harald Ludwig from Vancouver, Canada.
He's the eldest of four siblings, having two sisters and a brother.
His lucky number is 7 because he was born on May 7, at 7 minutes to 7, and weighed 7 pounds 7 ounces.
Alexander attended USC and lives full time in Los Angeles, California.
On the set of Race to Witch Mountain (2009), Dwayne Johnson gave him one of his personal guitars on his 16th birthday.
Is very close friends with AnnaSophia Robb.
The German name Ludwig means 'famous warrior'. Alexander plays the "famous warrior" Cato in The Hunger Games (2012).
Originally one of the three finalists for the the role of Peeta Mellark in The Hunger Games, but was later offered the Role of Cato By Director Gary Ross.
His paternal grandfather was German and his paternal grandmother was Belgian, from Antwerp. Alexander's mother has English, Scottish, and some German and Jersey (Channel Islander), ancestry; her family has recently lived in Canada, Australia, and New Zealand.