Ireland will send a full team of six women to the Olympics after wins for Moorhouse, Lehane and Walsh on Sunday.
They will join Kellie Harrington, Michaela Walsh and Aoife O’Rourke in Paris.
Many observers had felt Walsh should have qualified at the first World Tournament in Italy in March.
The Tullamore fighter then had her selection questioned by Amy Broadhurst who subsequently transferred to Great Britain when Walsh was chosen ahead of her for the trip to Thailand.
In the end Walsh let her boxing do the talking and she left nothing to chance with a dominant win over Ani Hovsepyan from Armenia.
Ashbourne school teacher Lehane also had a 5-0 win over Hanna Lakotar from Hungary while Moorhouse beat Bulgarian Zlatislova Chukanova 4-1.
The only blemish for Ireland on the final day of competition was a defeat for super-heavyweight Martin McDonagh.
It was all to play for against Armenian Davit Chaloyan heading into the final round and the Irishman looked like he had done enough, but not according to three of the five judges who scored it for Chaloyan.
It meant that Aidan Walsh joins fellow Commonwealth Games champion Jude Gallagher, Jack Marley and Dean Clancy on the plane to Paris.
Ten boxers represents the largest ever Irish squad heading to an Olympics. Only Australia with 12 and Uzbekistan with 11 qualified more, with Brazil and Kazakhstan also reaching double figures.
It leaves Ireland as the leading European nation and with hopes of adding more Olympic medals to their legacy this summer.