Serena and Venus Williams walk hand-in-hand at the Miami Grand Prix

Serena and Venus Williams appeared to be in good spirits as they walked hand-in-hand at the Miami Grand Prix.

The tennis superstars looked effortlessly chic in stunning summer dresses as they stepped out at the Miami International Autodrome on Sunday.

Serena, 40, showed off her sensational physique in a vibrant red halter-neck gown adorned with floral patterns.

She let her outfit do all the talking as she simply accessorised her look with a dainty gold necklace and carried a black handbag.

The 23-time Grand Slam winner shielded her eyes from the sunshine with an oversized pair of silver sunglasses and styled her golden locks in a blunt bob.

Meanwhile, former tennis world No. 1 Venus, 41, stunned in a blue floral dress with puffed sleeves and a white collar as she held hands with her younger sister.

She accentuated her striking features with a bold slick of mascara and styled her chocolate tresses in a straight fashion.

Serena was also seen laughing and joking with Spice Girl Geri Horner, 49, who captured attention in a white ensemble.

It comes after Serena opened up about how she's guiding her four-year-old daughter Alexis Olympia Ohanian Jr. to play tennis.

Appearing on the Ellen Show earlier this month, Serena insisted that she is not pushing her daughter into the sport due to her young age.

'I love her so much,' the tennis icon said of her child - who she shares with Reddit co-founder Alexis Ohanian, 39 - after which she was asked by Ellen DeGeneres how Olympia is at tennis.

Serena said that Olympia has shown potential in the sport but will need more work in honing her skills 'if she wants to play tennis'.

She continued: 'But I don't push her, I don't push her because she's four... she's alright, I've seen