According to Tom Spilsbury, the consolidated seven-day rating for Doctor Who finale, The Timeless Children, was 4.69m (4.55m on televisions and 0.14m on other devices). It was the 30th most-watched programme of the week across all television.

Also reported by TV Zone…

RATINGS: The series finale of #DoctorWho consolidated to an underwhelming 4.69m according to 7-day figures (inc. devices), making it the 30th most-watched show of the week.

Not only is that the lowest of the series, it's the lowest 7-day rating since the show returned in 2005.

— TV Zone (@tvukzone) March 9, 2020