Sam Foster will be joined by The Duke and Duchess of Cambridge to celebrate the 73rd anniversary of the health service.
The NHS National Service of Thanksgiving will recognise the dedication and commitment of all those who have played their part in combating COVID-19 across the NHS, care sector, and beyond.
Sam Foster, who has worked on the frontline, administered the first Oxford/AstraZeneca COVID-19 vaccination in the world (outside a clinical trial) in January at the Churchill Hospital Vaccination Centre.
She said: "I am very honoured to have been invited to attend this special service of thanksgiving at St Paul's Cathedral to recognise the work of NHS staff during the COVID-19 pandemic on the occasion of the NHS Birthday. I will be proud to represent my colleagues, both clinical and non-clinical.
"I would like to take this opportunity to say a special thank you to, not only my colleagues at OUH and the University of Oxford who have gone the extra mile to care for our patients and for each other during the COVID-19 pandemic, but also everyone else who has pulled together and supported us.
"This includes a 'thank you' to all the volunteers, including our Oxford Hospitals Charity, and members of the Oxfordshire community for the remarkable support which we in the NHS have received since the start of the pandemic, and for which we are incredibly grateful."
Others joining Sam at the heart of the socially distanced event in London include members of the University of Oxford team who helped develop the Oxford/AstraZeneca COVID-19 vaccine, Professor Dame Sarah Gilbert and Professor Sir Peter Horby.
Also in attendance will be Dr Ashley Price, a member of the team who treated the very first patients with the virus in this country, and May Parsons, who administered the first vaccine outside of a trial.
The service will be led by the Very Reverend Dr David Ison, Dean of St Paul's, and the Right Reverend and Right Honourable Dame Sarah Mullally, Bishop of London.
Among the congregation will be NHS England chief executive Sir Simon Stevens, matron May Parsons, who administered the first Covid-19 vaccination outside clinical trials.
Later, William and Kate will host the NHS Big Tea in the gardens of Buckingham Palace to pay tribute to the work of NHS staff who have gone above and beyond in tackling the pandemic.
They will meet staff ranging from respiratory ward nurses, counsellors and care workers, to those working in non-clinical roles including catering managers and housekeeping co-ordinators.
The NHS Big Tea is organised by NHS Charities Together and is a national celebration of the health service, offering the opportunity for communities to come together for a moment of reflection and to thank staff and volunteers for the role they have played throughout the pandemic.
The event hosted by the duke and duchess is one of thousands of Big Teas taking place on Monday in homes, hospitals, schools and community spaces across the UK.