The tree was planted in the newly-named Hopkins’ Field during a memorial service attended by friends, family and colleagues.
Hopkins, who died suddenly in January this year, is widely credited with being the driving force behind the parklands and in particular ensuring the focus on sustainability and biodiversity became a reality.
As the parklands and public realm project sponsor at the Olympic Delivery Authority between 2007 and 2011, he selected and oversaw the team which designed and delivered more than 100ha of open space in the Olympic Park.
The tree was planted by John’s children, Rosie and Jack, and fiancée, Laura, along with Dennis Hone, chief executive of the London Legacy Development Corporation, Nick Serota, director of the Tate and former Olympic Delivery Authority (ODA) board member and Jo Watkins, past president of the Landscape Institute.
Chief executive of the London Legacy Development Corporation Dennis Hone said the memorials were fitting ways to remember John’s "huge contribution."
"His vision and expertise ensured the parklands were one of the most loved attractions by many of the visitors to the Park, during the London 2012 Games and will be enjoyed by millions more as Queen Elizabeth Olympic Park begins to reopen from this summer."
Past president of the Landscape Institute Jo Watkins said he was happy and honoured to be Hopkins’ friend.
"He was undoubtedly at the point of becoming one of the finest landscape architects of our generation and yet most of all I shall remember him with great fondness for his love of life, football and good company.
"The creation of the Queen Elizabeth Olympic Park is quite simply his most fitting tribute."
Hopkins Field is a four-acre riverside grassy meadow sown with thyme, daisy, hawkbit, red clover and other nectar-rich species.
His fiancée Laura Adams, who is executive director at Shelby Farms Park Conservancy, said that he had inspired many people with his "big picture approach to urban planning."