This is trickier to answer than it seems. Bird and Radja apart, there is also
-Ramón Rivas (Puerto Rico, Seoul 1988). He played for the C's in the 1988-89 season.
-Stojko Vranković (Croatia, Barcelona 1992). He played for the C's for two seasons (1990-92).
There are some other players who have participated in Olympics though they were not in our roster at the time:
-Carlos Arroyo (Puerto Rico)
-Nenad Krstić (Serbia)
-Aleksandar Pavlović (Montenegro)
-Žan Tabak (Croatia)
-Rubén Wolkowyski (Argentina)
There are also several C's players that had good careers with their national selections although they did not play in the Olympics (eg Jiří Welsch); players who have played for the C's but were not on our roster when they played for team USA (Vin Baker, Gary Payton, Ray Allen, Kevin Garnett ,Shaq, Marbury, Prince as mentioned by Moranis); and Dominique Wilkins who played in the 1994 FIBA World Championship some months before signing with the C's for the 1994-95 season but never played in the Olympics (like Pierce); Joel Anthony and Olynyk had a similar situation with Canada (played in FIBA World Championships but not Olympics)
For a list of players who have played for the C's