The 26-year-old has seen and done it all in the sport having competed at the last two Olympics in Beijing and Athens and winning double gold at the 2006 Commonwealth Games.
Now coached by Ian Armiger, the Loughborough University swimmer will race in the 200m freestyle and has also qualified for the 4x200m freestyle relay.
McClatchey – whose uncle Alan won bronze in Montreal in 1976 – said she is enjoying training once more despite the weight of expectation on the home team.
“I’ve trained completely different and I’ve been with a new coach for about a year-and-a-half now,” said McClatchey.
“I think the main thing is that I’m enjoying it a lot more – it’s not becoming a mundane task of being in and out of the pool every day. I’m really enjoying what I do and that’s helping.
“We’ve got such a fantastic team as well, of support staff and swimmers - I think we’re all really buzzing and hoping to do really well this summer.
“We not necessarily seeing it as we’re under more pressure, which we’re putting on ourselves. We’re just really looking forward to the whole experience and just want to win medals.
“But we’ve got such great talent among the swimming team so I’m sure that we’ll do really well, but we don’t go in thinking we’re going to win X number of medals, we’re thinking we’ll try and do our best and try and get a medal. Hopefully we’ll do really well.”
McClatchey made her Olympic bow as an 18-year-old, helping the British 4x200m freestyle relay quartet to fifth in 2004.
But despite a wealth of experience, the Portsmouth-born swimmer admits the build up to the London Games has been the best yet.
“I’ve had two other experiences of this before Beijing and before Athens and this was by far the best I’ve had so far. Everyone was just so friendly and it’s been so organised and I’ve really enjoyed it.
“Because it’s a home Olympics, the excitement has sky-rocketed and I can’t believe it’s in London in the summer.
“I know the build-up is big at the moment with the torch relay, but it’s amazing and I can’t believe it’s happening and it’s going to be such a great experience in the summer.”
McClatchey was left sweating on her place after missing the British Gas Swimming Championships with illness, but with selection successfully negotiated she added: “I’d love to be able to contribute a medal, but I’ve kind of been fortunate to win world and European medals – but not actually as champion.
“To be honest, I’d love to win an Olympic medal as that’s my main inspiration so I will do everything I can in my training and I would love to be able to contribute to the medal table and help Great Britain.”