Alex Henteloff (born 23 May 1942; age 82) is the actor who played Dr. Nichols in Star Trek IV: The Voyage Home.
Other films in which he has appeared include Hardly Working (1980, with Roger C. Carmel), 52 Pick-Up (1986, with John Glover and Clarence Williams III), and Payback (1999, with Gregg Henry, David Paymer and John Glover).
He is perhaps most famous for his recurring role as "Arnold Ripner" on the television series Barney Miller, which starred Ron Glass, Gregory Sierra, George Murdock and James Gregory. He was also among many Star Trek performers to have a role in Centennial (1978, with Michael Ansara, Henry Darrow, Cliff DeYoung, Robert DoQui, Robert Easton, Brian Keith, Sally Kellerman, Stephen McHattie, Nick Ramus, Clive Revill, Steve Sandor, James Sloyan, Morgan Woodward, and Anthony Zerbe). Henteloff also appeared in Code Name: Diamond Head (1977, starring France Nuyen and Ward Costello), and co-starred with Ashley Judd, Jeffrey Combs, and Steven Culp in Norma Jean & Marilyn (1996).