The Tube drivers' strike was announced after Aslef members voted by 9-1 in favour of strikes in a long-running row over extra pay for working on Bank Holidays.
The ballot result shows the strength of feeling that remains on this issue. The union is committed to finding a solution which offers voluntary working and compensates those who do attend.
It will be the third successive Boxing Day walkout by Tube drivers in a dispute over Bank Holiday pay which dates back to an agreement in 1992.
The stoppage will disrupt Tube services on a busy day in the capital, causing chaos for shoppers, sports fans and visitors.
Talks have been held at the conciliation service Acas, but the dispute remains deadlocked.
More top news
George Michael died in December last year at the age of 53.
PC Keith Palmer, 48, stabbed by Khalid Masood while on duty in the grounds of the Palace of Westminster last Wednesday.
Those gathered on the bridge fell silent at 2.40pm - the time the first call was made to police exactly seven days ago.