The group posted pre-tax profits of £325 million for 2020, down 39% from £530 million in 2019 as revenues fell 16% to £2.8 billion.
Underlying earnings dropped 21% to £573 million, which it said was better than expectations thanks to a strong end to the year and £116 million of cost savings.
ITV said the first quarter of 2021 was challenging due to the lockdown, with total ad revenues set to be down around 6%, but added its performance was bouncing back from the crisis.
Nearly all its programmes are back in production and total ad revenues are set to be up by around 8% in March and by between 60% and 75% in April, according to the group.
Carolyn McCall, chief executive of ITV, said: “While total revenues and profits were down our financial performance was ahead of expectations driven by a strong end to the fourth quarter and our firm control over costs.
“We are encouraged by the road map out of lockdown. We are seeing more positive trends in the advertising market in March and April and the majority of our programmes are now back in production.
“However, there remains uncertainty in all markets around the world with the potential risk of lockdowns, which if they materialise will affect revenues.
“We are committed to taking further cost out of the business while further investing to accelerate the delivery of our strategy and digital transformation.”