Locke was nominated for the Oscar for best supporting actor for her role in her first ever film, The Heart is a Lonely Hunter in 1968.
"I had never been on a movie set but it was like coming home," she told Variety — the Hollywood bible — in 1978.
Locke died on November 3 in California after a long battle with breast and bone cancer but her death was only reported on Friday, December 14.
#SondraLocke (1947 — 2018).
— Juan Ferrer (@JuanFerrerVila) 14 December 2018
Sondra Locke and Clint Eastwood. pic.twitter.com/mxZoRH85Vf
Although her film roles dried up in the 1980s the bubbly blonde remained in the headlines a lot longer, mainly because of her relationship with Clint Eastwood which turned extremely sour.
Despite her Oscar nomination in 1968 Locke only really reached the top level in Hollywood when she was cast to play Eastwood's love interest in the 1976 western The Outlaw Josey Wales.
Eastwood was married at the time but seduced Locke on set.
"We were almost living together from the first days of the film," she said later.
God bless you Sondra Locke — "right turn Clyde"….give him all our love when you see him…#SondraLocke
— smilingmrkev (@smilingmrkev) 14 December 2018
Locke and Eastwood became a couple and acted opposite each other in Every Which Way But Loose, Any Which Way You Can, The Gauntlet and Sudden Impact.
Locke directed her first film, Ratboy, in 1986 but it was a commercial and critical failure.
Just found out Sondra Locke passed. A lot of talk today is gonna regard her ex-husband but I think we should remember her as the great actress she once was, as well as her performances in films like The Heart is a Lonely Hunter, which she was Oscar nominated for. #RIPSondraLocke pic.twitter.com/SD9XdyOAbB
— Joe Anthony Myrick (@WamBamItsJAM) 14 December 2018
Eastwood, a notorious womaniser, cheated on her with numerous women and the couple split up acrimoniously in 1989 and for the next decade she pursued him with increasingly bitter litigation.
She sued him for palimony and he changed the locks on their Bel-Air home to keep her out.
Eventually they reached a settlement where he set up a film development deal for her at Warner Brothers in exchange for her dropping the suit.
Love that @MSN think #SondraLocke being Clint Eastwood's girlfriend for 13 years is more impressive than the fact she was nominated for an Oscar pic.twitter.com/nFDYof9mfG
— Ros Metcalfe (@rosmetcalfe) 14 December 2018
In 1995, she sued him for fraud, claiming the deal with Warner Brothers was "bogus" and the studio had rejected 30 or so projects she proposed.
Her attorney Peggy Garrity, claimed Eastwood committed "the ultimate betrayal" by arranging the deal to keep her out of work.
She vented her spleen against Eastwood in her 1997 autobiography, The Good, The Bad and the Very Ugly, and claimed he had derailed her acting career.
RIP Sondra Locke. Who wants to see Ratboy with me? pic.twitter.com/VsLLXG3Zfg
— Tom Silvestro (@tomsilvestro) 14 December 2018
Locke also claimed he made her have an abortion in the late 1970s because it did not "fit in with their lifestyles" while at the same time fathering two children with other women.
After years of obscurity she appeared in one last film, Ray Meets Helen, with Keith Carradine.