Mohamed Nagi and Charlotte Buckley topped the times at the Hounslow Mini Marathon trials last Saturday.
More than 80 boys and girls aged 11 to 17 were aiming to finish in the top seven of their age categories to secure a place on Team Hounslow.
Successful competitors will represent the borough and race over the last 5km of the actual London Marathon course.
Nagi (U17 boys) posted a time of 18 minutes, 46 seconds, while Buckley (U13 girls) produced a time of 20 minutes, 58 seconds.
Councillor Sachin Gupta, Hounslow Council’s cabinet member for public health and leisure, said: “The Virgin Money Giving Mini London Marathon has unearthed a number of British athletics stars including, Scott Overall, David Weir, Shelly Woods and Mo Farah, who represented the London Borough of Hounslow, so it’s a very prestigious event.
“It’s little wonder that the competition to be in Team Hounslow this year was amongst the toughest ever.
"Congratulations are due to the organisers and to all who took part.
“We’ll be wishing them all the best of luck in April.”