McDonnell announced the plans at a pre-Budget speech in London earlier today, adding that Labour also shares the widely-held goal of clamping down on tax avoidance.
"Transparency and fairness is at the heart of building a decent, open society. This will help restore public trust in the tax system – and help clamp down on any avoidance," McDonnell said.
It comes after several senior politicians - including then home secretary Theresa May - last year published their own tax documents in the wake of the Panama Papers scandal.
A Downing Street spokesman said today he was unaware of any plans for May to repeat the disclosure this year.
McDonnell also re-committed Labour to a "right to own" plan first announced last year, under which employees would be given first refusal on bringing forward a plan to take ownership of their company.
Chancellor Philip Hammond will present the government's own spending plans at the final spring Budget next week.