The sad news of the split was broken by US Weekly, to whom a source revealed that the pair were no longer in a relationship.
Actress Halle, 51, then appeared to verify the announcement by sharing a candid snap to her Instagram Stories account, showing some ropes twisted in the the shape of a heart, along with the caption: 'Done with love'.
However, neither Halle or Alex have released an official statement on the matter.
Halle and Alex pictured together in September 2017
The couple publicly confirmed that they were seeing each other in September of this year, when they both posted sweet black and white snaps on social media referring to each other as 'my balance.'
Halle and music producer Alex then began making appearances at events together, including a stint at Halloween where they both dressed up as mummies.
'Halle and Alex seemed particularly close,' an insider told US at the time. 'They were laughing intimately at the table. They kept to themselves and stayed close together. They seemed like they were having a nice time.'
Mum-of-two Halle has been married three times previously, to baseball player David Justice, who she divorced in 1997, singer Eric Benét, who she split from in 2005, and Oliver Martinez, who she ended her marriage with in 2016.
She welcomed daughter Nahla Ariela with model Gabriel Aubry in March 2008, and subsequently had a son, Maceo Robert, with Oliver in October 2013.
In 2017, Halle gave an interview about her experiences of heartbreak and divorce, admitting that she's 'kind of anti–fairy tales today'.
'I've often felt guilty and responsible. I've suffered a lot of pain and anguish,' she confessed.
'In every one of those situations, as hard — and sometimes embarrassing — as it was, I learned so much about myself.'
'Those relationships provided me with lessons that got me to where I am right now. For that, I'm grateful. But it has been hard. It's been a difficult part of my life.'