  A topological space $X$ is $\kappa$-Fr\'{e}chet--Urysohn if for every open
subset $U$ of $X$ and every $x\in \overline{U}$ there exists a sequence in $ U$
converging to $x$. We prove that every $\kappa$-Fr\'{e}chet--Urysohn Tychonoff
space $X$ is Ascoli. We apply this statement and some of known results to
characterize the $\kappa$-Fr\'echet--Urysohn property in various important
classes of locally convex spaces. In particular, answering a question posed in
[7] we obtain that $C_p(X)$ is Ascoli iff $X$ has the property $(\kappa)$.
