Described as suffering a "crisis" by the National Union of Journalists (NUJ), the industry is criticised for cutting jobs and offering low pay for long hours. As a result of job losses the quality of journalism in print, radio and TV was suffering, the union said.
Manchester, venue for the Society of Newspaper Editors annual conference, is expected to see the biggest rally. Other marches and events are to be held, with broadcasting workers union Bectu also joining in.
NUJ president Michelle Stanistreet said: "Thousands of journalists from all sectors of the media will be joining together to protest against the crisis taking place in our industry.
"Job cuts, long hours and below inflation pay deals are rife and pensions are increasingly under attack. "The squeeze is being put on journalists and publishing workers on a daily basis and the inevitable result is that quality and standards are suffering."
The campaign coincides with the start of union talks with the BBC over redundancies after the corporation announced last month it would cut 2,500 posts to bridge a £2bn funding gap. The Stand Up For Journalism campaign is also being supported by media workers in other European countries.