Katz Yefim Borisovich (15 November 1947, Riga) — biologist.

Son of Anna Smertenko (1922, Kyiv) and Boris Katz (… — 1974, Riga). Since 1967, he has worked as a research fellow and later senior research fellow at the Institute of Biology of the Latvian Academy of Sciences.

In marriage with Vera Izrailevna Katz (née Izrets) (1949, Riga), he had two sons: Leonid Katz (1973, Riga) and Boris Katz (1977, Riga). In 1992, Yefim Katz received permission to emigrate to the United States.

Vera Izrailevna Katz (née Izrets) (1949, Riga) — wife
Leonid Katz (1973, Riga) — son
Boris Katz (1977, Riga) — son
Anna Smertenko (1922, Kyiv) — mother
Boris Katz (… — 1974, Riga) — father
Lev Lazarev (1950, Riga) — half-brother (from mother’s second marriage)