The Guardian is increasing its weekday print cover price by 20p to £2 a day from Monday 18 April.
The move comes as publisher Guardian Media Group seeks to curb operating losses which it has said total £58.6m for the year to the end of March.
The Guardian's weekday cover price rose by 20p from £1.60 to £1.80 a year ago.
The price of the title on Saturdays is increasing by 20p to £2.90. The Observer is going up by 10p to £3.
A Guardian News & Media spokesperson said: "Our readers recognise the high quality of our journalism – such as our ongoing coverage of the Panama Papers – and their loyalty is something that we truly value.
"However, this is an increasingly challenging market for all newspapers and by raising the cover price we are able to keep investing in our journalism and all our print and digital products, ensuring that both the Guardian and The Observer can continue their proud history of powerful journalism."
Guardian News and Media contionues to make all its journalism available for free online.
Following the closure of The Independent, The Guardian is now the lowest selling UK national newspaper title, according to ABC. In February, its sales fell 8.5 per cent year on year to an average of 161,152 per day.
The Financial Times is the only UK national newspaper which is more expensive, at £2.70 per day. The i sells for 40p, the Daly Telegraph costs £1.40 and The Times costs £1.20.
|The Sun on Sunday||1,412,453||-5.03||-5.2||58,889|
|The Mail on Sunday||1,381,077||-0.5||-4.77||66,596|
|Metro (Associated Newspapers) UK Group||1,347,505||-0.04||0.16|
|London Evening Standard||902,005||0.4||2.14|
|The Sunday Times||766,001||-0.57||-2.68||37,495|
|The Daily Telegraph||472,936||0.19||-1.46||5,358|
|The Sunday Telegraph||356,975||0.54||-4.15||4,932|
|Daily Star – Sunday||298,625||-0.17||12.96|
|Independent on Sunday||90,248||-1.52||-5.9||48,577|