The 34-year-old was presented with his medal by the Princess Royal at a Windsor Castle investiture ceremony.
Strauss's men won the series, which ended in the new year, 3-1 to claim England's first victory on Australian soil since 1987.
"It was certainly one of the proudest moments of my career because for us winning the Ashes away from home is a bit like the holy grail," the South African-born opening batsman said after the event.
"It's not something that many English sides have done previously, so it makes it more satisfying when you are able to achieve that."
England next travel to India for a one-day series which begins on Friday, October 14.