Muljadi (formerly known as Ang Tjin Siang 翁振祥) was a world class badminton player who represented Indonesia between 1963 and 1973.

Muljadi's career spanned two separate eras of Indonesian domination of the then triennial Thomas Cup (men's international team) competition: 1958 to 1964 and 1970 to 1979.

Though he occasionally dropped matches in earlier Thomas Cup rounds, he was undefeated in singles (6-0) in four consecutive final round showdowns (1964, 1967, 1970, 1973),[1] a record unmatched by better known teammates such as Ferry Sonneville, Tan Joe Hok, and Rudy Hartono.

He won several Indonesian national singles titles during the 1960s as well as the French Open (1966), the Asian Championships (1969), and individual honors in the Asian Games (1966).

This biographical article relating to Indonesian badminton is a stub.