The church of Saint-Nizier in Lyon is dedicated to him. There is an early life of Nicetius which can be found in Vita Nicetii Episcopi Lugdunensis, ed.
B. Krusch, Monumenta Germaniae Historica Scriptores Rerum Merovingicarum III pp. 518–524 and is translated online here Gregory of Tours - who refers to Nicetius as his uncle- also wrote a supplementary life to him in his Vita Patrum.