Walter, who has held the position since March 2023, has attributed his resignation to personal reasons.
He played an instrumental role in South Africa's recent successes on the global stage. Under his leadership, the Proteas made history by reaching their first-ever ICC Men's T20 World Cup final in 2024, where they finished as runners-up to India in Barbados.
A record run of eight consecutive wins underpinned the campaign. His tenure also saw the 50-over side reach the semi-finals of the ICC Men's Cricket World Cup 2023 in India. In his time at the helm, Walter oversaw the national side in 36 One-Day Internationals and 31 T20 Internationals, with series wins against Netherlands, Australia, Ireland and Pakistan.
His final assignment was the ICC Champions Trophy 2025 in March, where he led the Proteas to another semi-final appearance, this time against New Zealand in Lahore.
"Coaching the Proteas has been an incredible honour, and I am immensely proud of what we have achieved together," said Walter. "The players, support staff, and the South African cricketing community have been fantastic throughout this journey. While it's time for me to step away, I have no doubt that the team will continue to grow and reach even greater heights."
Director of National Teams and High Performance Enoch Nkwe said: "Rob has done an immense job for South African cricket over the past two years.
"It is also important to recognise Rob's commitment to expanding the talent pool across both formats. While in charge, he ensured that emerging players had the opportunity to develop and make their mark at the highest level, which will be critical for the future of the Proteas.
"We have a busy period of white-ball cricket over the next two years as we build towards the Cricket World Cup on home soil. His successor will continue to work towards that 50-over World Cup campaign, along with next year's T20 World Cup."
CSA Chief Executive Officer Pholetsi Moseki added: "Rob played a significant role in the rebuilding of the Proteas brand on the international stage. During his two years in charge, we have witnessed a significant increase in faith in South African cricket, largely due to the team's performance.
"His professionalism and work ethic have been exemplary, and he will undoubtedly be missed. On behalf of Cricket South Africa, we wish him all the success in the future."
A successor will be announced in due course.
South Africa produced a dominant performance to beat Australia by an innings and 31 runs in the second Test at St George's Park in Gqeberha on Thursday, levelling the series at 1-1.
South Africa produced a commanding performance to defeat Australia by an innings and 31 runs in the second Test at St George's Park in Gqeberha, with captain Temba Bavuma leading the way with a magnificent 179.
Marco Jansen took a five-wicket haul as the Proteas skittled Australia out for just 99, before the tourists found themselves in trouble following-on at 156-4, still trailing by 170 runs.
Proteas captain Temba Bavuma struck his fifth Test century, and the best of his career, as the hosts dominated Australia on the third day of the second Test at St George's Park in Gqeberha.
