\documentclass{article}

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[ngerman]{babel}
\usepackage[xindy,automake]{glossaries}

\makeglossaries

\newglossaryentry{Uberlingen}{name={{Ü}berlingen},
  description={a place}}

\begin{document}

\gls{Uberlingen}

\printglossaries
\end{document}
