The star, 31, had not told her mother Dudu who she had not seen for four years, about the return journey, and also had not seen her father Peter for four years.
The professional dancer shared a video of herself at Heathrow Airport on Instagram as she charted the emotional journey.
She told fans in the video: “I’m on my way home. I haven’t been home in four years. I haven’t seen my mum in four years, haven’t seen my dad in four. She doesn’t know I’m coming home.”
The clip cut to the star loading her luggage before giving the camera a thumbs up on the plane.
She was then filmed walking up to her family’s front door for the surprise Christmas reunion.
The dancing champion said in a caption: “Finally after years I was able to go home to South Africa.
“Decided to surprise my family and not tell them I’m coming home just to see their expressions, mom was speechless (touched me all to see if I was real, dad couldn’t stop smiling and my god mother cried her eyes off).
“To say I was emotional is an absolute understatement.
“I have been waiting 3-4 years to hold my moms, dad, sister, nieces and nephews in my arms and just spend time with them NOT through a screen.”
Oti, whose sister Motsi is a judge on the show, said the pandemic had taught her that family “should never be taken for granted”.
The dancing champion is set to replace John Barrowman as a judge on Dancing on Ice in the New Year.
She signed up to become a judge on ITV’s The Masked Dancer earlier this year alongside Davina McCall, Mo Gilligan, and Jonathan Ross.