Both were part of the Three Lions’ World Cup campaign in Russia this summer, in which Gareth Southgate’s team finished fourth.
Vardy, 31, has been a regular in England squads since May 2015, making his debut as a substitute against the Republic of Ireland in June of that year.
The following season, Vardy and his Leicester teammates secured a shock title win, with the forward breaking a Premier League record by scoring 13 goals over 11 consecutive matches.
Vardy’s last appearance for England was as a substitute during the 2-1 World Cup semi-final defeat to Croatia.
In total, the Sheffield-born star scored seven goals in 26 appearances for the national side.
Vardy initially shared his thoughts with England manager Southgate at the start of the Premier League season and was given time to mull over his decision, according to Sky sources.
However, the period of reflection hasn’t altered his view.
Announcing his decision, Vardy told The Guardian: “This has been on my mind for a while.
“I’m not getting any younger and you can see, to be fair to the gaffer, he wants to make it more youthful, which obviously had its benefits during the World Cup – we got to the semi-finals and finished fourth, which is equal to the furthest we have ever been on foreign soil.
“So I just said to Gareth that I think it’s probably best from now on, especially with the way he wants to go, to bring youngsters in who he thinks have got the ability and start nurturing them into international football.”
Much like Liverpool’s James Milner, Vardy has told Southgate he would be prepared to return in exceptional circumstances, such as an injury crisis or an exceptional run of form.
However, it is highly likely he won’t play for England again.
Meanwhile, Cahill has told Chelsea TV: “I think in terms of my international future I think it’s time I take a step back now. I feel that it’s the right moment to do that.
“I have been hugely proud of what I have achieved in terms of over 60 caps, I’ve captained my country on a few occasions which has been a huge honour, it’s something I have been really proud of in terms of my career.
“I can see now it’s going in a younger generation and I think for me to take a step back now is the perfect time.”
Cahill was first called up to the England squad in 2009 but had to wait more than a year for his first cap, which came as a substitute against Bulgaria in September 2010.
He was also part of the national squad at the 2014 World Cup and 2016 European Championship.
Cahill’s single appearance at this year’s World Cup came in England’s group game against Belgium.
Southgate had planned to include Vardy in his squad for England’s upcoming UEFA Nations League match against Spain on 8 September.
Cahill may have struggled for a call-up, with the 32-year-old having not been picked for any of Chelsea’s first three Premier League games this season despite being the club captain.
The England manager will now use the opportunity to give other players a chance.