The Edinburgh-based group said profit increased by 22.6% to £31.5m, while revenues were down 6.8%, to £242.3m.
However, total operating costs were cut by 6.7% to £191.7m.
The figures were released as Johnston confirmed that shareholders had overwhelmingly backed a deal to buy the i newspaper from ESI Media for £24m.
It said the acquisition would give the company "numerous revenue and cost synergy opportunities", contribute positively to earnings and "allow us to accelerate growth in digital, and help stabilise our circulation revenues".
In its annual results statement, the owner of The Scotsman and more than 200 other titles said "challenging trading conditions" in the second half of last year had continued into 2016.
Total revenues for the first eight weeks of this year were down 13% "against strong year-on-year comparatives" in the first quarter of 2015.
Other Johnston Press financial highlights for 2015:
In January the group revealed plans to cut editorial jobs across its operations in the UK, as part of a drive to cut costs following a decline in revenue.
Chief executive Ashley Highfield said: "We have reduced costs to maintain profitability, reset our portfolio and refocused on priority markets with attractive audiences that offer the best opportunity for growth.
"Success in driving our national display advertising business in 2015 and the rollout of our local display advertising sales force initiative gives me confidence for the future despite the fact that the market remains difficult."
The company stated that this year it would "focus on and invest in our primary brands, operating in growth markets with attractive audiences".
Johnston added: "We have identified a number of newsbrands that are now considered non-core and such will be either divested or run with less costs, reflecting the medium-term outlook for the identified assets that fall into this category.
"The company will run a formal process, with advisers, to market defined asset groups for sale during 2016. Interest by third parties, enquiring about assets, has been encouraging so far."

"Hope made a poor decision that has resulted in a negative impact on US Soccer and her team-mates," head coach Jill Ellis said.
Solo, 33, will now miss matches on 8 February against France and 13 February against England.
This month, domestic violence charges against Solo were dropped.
In 2012, Solo, tested positive for a banned substance a month before winning a second Olympic gold medal.
She maintained she was not aware the pre-menstrual medication she had been prescribed contained a banned substance and she was cleared of any wrongdoing.
The US are preparing for the Women's World Cup in Canada in June when they will aim to win their third title following victories in 1991 and 1999.
The latest incident surrounding Solo concerns a training camp being held by the team in Carson, California.
Solo's husband, former Seattle Seahawks NFL player Jerramy Stevens, was arrested on suspicion of driving under the influence in Los Angeles in the early hours of Monday morning.
Media reports claimed Solo was in the car but she was not cited in the incident by Manhattan Beach police officials.
Solo tweeted: "I think it's best for me to take a break, decompress from the stress of the last several months and come back mentally and physically ready to positively contribute to the team."
Cost-cutting measures helped publisher Johnston Press achieve a rise in adjusted pre-tax profit last year, despite falling sales.
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The United States women's team goalkeeper Hope Solo has been suspended for 30 days by US Soccer following an incident during a training camp.