The centre-back has played a key role in England's march toward the last four, impressing at both ends of the pitch with his aerial dominance.
After finishing second in their group, England have seen off Colombia in the Round of 16 and Sweden in the quarter-finals - and could now go one better than Belgium, who topped Group G, if they beat Croatia in the semis.
Maguire isn't getting carried away by what may lie ahead, instead focusing on what will be a tough game against some world class players - but says England have enough quality of their own to produce a big performance.
"We're still focused. We want to go and believe we can go all the way and win the tournament.
"We've got good players in the camp, good staff, good management. The nation's right behind us and it's a big game, one I'm looking forward to.
"It's the biggest game of everyone's career to-date without a doubt, so I'm sure we'll all be up for it, be ready for it and prepare as well as we can."