LU TP 98-17, hep-ph/9808421 August 1998 Double Chiral Logs J. Bijnens, G. Colangelo, G. Ecker Abstract: We determine the full structure of the leading (double-pole) divergences of O(p^6) in the meson sector of chiral perturbation theory. The field theoretic basis for this calculation is described. We then use an extension of this result to determine the p^6 contributions containing double chiral logarithms (L^2), single logarithms times p^4 constants (L x L_i^r) and products of two p^4 constants (L_i^r x L_j^r) for F_\pi, F_K/F_\pi, K_{l3} and K_{e4} form factors. Numerical results are presented for these quantities. published in Phys. Lett. B441(1998)437