The centre-back has produced a string of impressive performances to earn praise from his boss after helping the Trotters concede just 15 Premier League goals this season.
And Megson now believes that Cahill stands a chance of forcing his way into the plans of England chief Fabio Capello.
Former England Under-21 international Cahill would have to dislodge the likes of John Terry, Rio Ferdinand, Matthew Upson and Joleon Lescott, but Megson does not doubt his player's ability.
"Everybody has an opinion," Megson told Sky Sports News. "I wouldn't swap Gary for too many others.
"When they (England) send their scouts out Gary has to play well on that day."
Megson believes Cahill, 22, deserves his chance after Chelsea youngster Michael Mancienne was named in the England squad for Wednesday's victory over Germany.
The Reebok Stadium manager also feels that Cahill should be offered an opportunity following the previous international inclusion of Middlesbrough's David Wheater.
Megson added on Bolton's official website: "Wheater has had the call in front of him, Mancienne has had the call in front of him and Upson has had the call in front of him.
"We have the fourth best defensive record in the Premier League and Gary Cahill is huge part of that."
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