Winter was born in London, England. His mother, Gregg Mayer (born 1940), is a New York-born American who was a former Martha Graham dancer and founded a modern-dance company in London in the mid-1960s. His father, Ross Albert Winter (born 1937), was Australian and danced with Winter's mother's troupe. Winter received training in dance as a child. When he was five, his family moved to Missouri, where his father ran the Mid-American Dance Company, while his mother taught dance at Washington University in St. Louis. The two divorced in 1973.
Winter is Jewish. He was married to Sonya Dawson with whom he had a son, Leroy Winter, born in 1998. In Some time, he and Sonya Divorced. In 2010, he then married Ramsay Ann Naito and both has had two children since then. Winter maintains dual British and American citizenship.
Winter moved to New York City in 1978 and began performing as an actor on and off Broadway. In 1983, he was accepted into the Film School at New York University (NYU). While at college, he met fellow aspiring filmmaker Tom Stern. The two collaborated on a number of 16mm short films and both graduated with honours.
As an actor, Winter spent many years on Broadway with supporting roles in productions of The King and I, Peter Pan, or The Boy Who Wouldn't Grow Up, and the American premiere of Simon Gray's Close of Play at the Manhattan Theatre Club. After completing NYU film school, he and Tom Stern moved out to Hollywood, where the two wrote and directed a number of short films and music videos. Winter continued to find work as an actor, landing notable roles in such big productions as The Lost Boys and Rosalie Goes Shopping. In 1989, Winter found international success when he co-starred with Keanu Reeves as Bill S. Preston in the smash-hit comedy Bill & Ted's Excellent Adventure and its 1991 sequel, Bill & Ted's Bogus Journey.
Following the success of Bill & Ted, Winter and creative collaborators Tom Stern and Tim Burns were hired to develop a sketch comedy show for MTV. The result, 1991's The Idiot Box, was a success for the network, but the channel's budgetary problems prevented them from filming additional seasons, and it was canceled after six episodes. Winter, Stern and Burns accepted a $12 million deal from 20th Century Fox to film their own feature film, which would end up becoming 1993's Freaked. While the film was never widely released, despite positive reviews from The New York Times, and Entertainment Weekly, Freaked went on to become a cult favourite, through festivals, TV and DVD, and was cited by Entertainment Weekly, on their list of Top Ten Comedies of the Nineties.
Winter did not return to directing until 1999, when he filmed Fever. The film was shown at film festivals worldwide, including Official Selection in the Director's Fortnight at Cannes. New York Daily News praised the film, calling it "a claustrophobic mind bender. Winter sustains an aura of creepiness worthy of Roman Polanski."
Winter directed the live-action adaptation of the hit Cartoon Network series Ben 10, which aired in November 2007 and garnered the highest ratings in Cartoon Network history. He directed its sequel, Ben 10: Alien Swarm which aired on Cartoon Network in November 2009 and captured over 16 million viewers in its premiere weekend. He has reportedly been chosen to write the screenplay for the Howard Stern-produced remake of Rock 'n' Roll High School. His latest project is a 3D-remake of the 1987 horror film The Gate which was scheduled for release in 2011.
In April 2011, Winter's Bill & Ted co-star Keanu Reeves confirmed that a third installment of the film series was underway. Winter's confirmed work on Bill & Ted 3 was still in progress in a 2014 article on the original film's 25th anniversary. In 2016, Winter said that he hoped the film would go into production in 2017. Reeves confirmed in February 2017 that the third film is being made, and the writers have a story. "Basically, they’re supposed to write a song to save the world and they haven’t done that" Reeves said about the plot of the movie.
Winter’s 2012 VH1 Rock Doc Downloaded earned worldwide critical acclaim at theatrical and festival screenings. Winter's multiple award-winning 2015 documentary Deep Web, had its world premiere at SXSW and a broadcast premiere in the U.S. on the Epix network alongside a global festival tour. The film went wide on September, 2015, opening as the #1 documentary on iTunes.
In July 2015, Winter began work on a biographical documentary of the rock guitarist and composer Frank Zappa. The Zappa Family Trust publicly gave its approval to Winter's plans for the film. The Kickstarter campaign for this project was the highest funded documentary in crowdfunding history.
Recently completed are two short documentary films for Laura Poitras’s Field of Vision: Trump's Lobby and Relatively Free, about imprisoned journalist Barrett Brown.
In 2014 he had a role in the thriller Grand Piano starring Elijah Wood and John Cusack playing The Assistant.
Alex Winter is also an outspoken advocate for technology and privacy rights.
He became interested in the Internet in the late 1980s. Winter said he began devoting a lot of his attention to the Internet not just because he liked technology, but also because "I found this community there." Winter liked the idea of large numbers of anonymous users discussing a variety of topics in an anonymous space. "I found that really striking then. And it seemed liked the beginning of something," he said.
Winter was an early user of Napster. He criticized media companies and news outlets for exaggerating how many people used Napster for digital piracy. "Napster was a huge threat to the power structure," Winter said.
Winter's interest in technology, the Internet and privacy inspired him to make the 2012 documentary film Downloaded, about internet file sharing and Napster, and the 2015 film Deep Web, about the Silk Road, bitcoin, and the dark web.Freaked (1993) (also co-writer, co-producer and actor [Ricky Coogin])
Fever (1999) (also writer and actor [subway passenger])
Deep Web: The Untold Story of Bitcoin and the Silk Road (premiered at film festivals beginning March 2015)
Smosh: The Movie (2015)
NYU Sight & Sound Project (mid-1980s) (student short film, released on DVD, also actor)
Squeal of Death (1985) (short film, aired on Night Flight and West Coast Cable, released on VHS and DVD, also co-writer and actor)
Aisles of Doom (1989) (short film, aired on Night Flight and West Coast Cable, released on VHS, also co-writer and actor [Grendel T.W. Ulcerous])
Stuart S. Shapiro's Impact Video Magazine (1989), includes, among others, Entering Texas a.k.a. Bar-B-Que Movie (VHS, also actor)
Howie Meets the Ghost of Environmental Disasters Yet to Come (1990) (short film for the Nigel Dick-directed Save the Planet: A CBS/Hard Rock Cafe Special, aired on CBS April 20, 1990, also actor)
The Idiot Box (1991) (MTV show, also co-writer and actor)
Meals on Wheels (1991 or 1992) (short film for The Playboy Channel's Inside Out late night anthology series, also co-writer and actor)
Tabla Beat Science: Talamanam Sound Clash (2003) (concert DVD, co-directed by Zane Vella)
Dirty Famous (2005) (VH1 pilot)
Ben 10: Race Against Time (2007) (Cartoon Network film, also executive producer and actor [Constantine Jacobs])
Ben 10: Alien Swarm (2009) (Cartoon Network film, also executive producer and voice actor [Nanomech])
Jimmy Kimmel Live! segments
The Andy Milonakis Show
Level Up (2012)
Red Hot Chili Peppers — "Knock Me Down" (1989)
Ice Cube — "Who's the Mack?" (1990)
Human Radio — "Me & Elvis" (1990)
Extreme — "Decadence Dance" (1990)
Ronny Jordan — "The Jackal" (1993)
Helmet — "Milquetoast" (1994)
Helmet — "Wilma's Rainbow" (1994)
Bomb the Bass feat. Carlton — "1 to 1 Religion" (1995)
Foetus — "Verklemmt" (1995)
Axiom Funk — "If 6 Was 9" (1996)
Bomb the Bass feat. Justin Warfield — "Bug Powder Dust" (1997)
Helmet — "Exactly What You Wanted" (1997)
Death Wish 3 (1985) — Hermosa (Director Michael Winner)
Medium Rare (1987) — (Director Paul Madden)
The Lost Boys (1987) — Marko (Director Joel Schumacher)
Haunted Summer (1988) — Dr. John Polidori (Director Ivan Passer)
Bill & Ted's Excellent Adventure (1989) — Bill S. Preston, Esq. (Director Stephen Herek)
Rosalie Goes Shopping (1989) — Schatzi Greenspace (Director Percy Adlon)
Bill & Ted's Bogus Journey (1991) — Bill S. Preston, Esq./Granny Preston/Evil Robot Bill (Director Peter Hewitt)
The Borrowers (1997) — TV Gangster (Director Peter Hewitt)
Grand Piano (2014) — Assistant (Director Eugenio Mira)
The Equalizer episode "Mama's Boy" (1985) — Jeffrey (director James Sheldon)
Bill & Ted's Excellent Adventures (1990) — Bill S. Preston, Esq. (voice) (directors Robert Alvarez, Don Lusk, Paul Sommer & Carl Urbano)
Sex, Shock and Censorship in the 90's (1993) — Stinx on Ice (director David Jablin, aired on Showtime September 10, 1993)
Bones episode "The Girl in the Gator" (2007) — Monte Gold (director Allan Kroeker)
Saul of the Mole Men 5 episodes (2007) — King Mole Man (voice) (director Tom Stern)
Robot Chicken 1 episode (2012) — Bill S. Preston, Esq., Steve Burns (voice)
Red Hot Chili Peppers — "Higher Ground" (1989) (directors Drew Carolan & Bill Stobaugh)
Red Hot Chili Peppers — "Knock Me Down" (1989) (director Drew Carolan)
Brother Cane — "Hard Act to Follow" (1994) (director David Hogan)