Coloccini has been linked with a move away from the club at the end of the campaign as part of an expected re-building project at St James' Park.
Argentina centre-back Coloccini asked to return to his homeland to sign for San Lorenzo in January last year due to what was described as a "personal matter" by manager Alan Pardew.
The former Milan and Deportivo defender agreed to stay on following talks with the club, and has now reasserted his loyalty to Newcastle.
"For sure. I’m going to be here," Coloccini told The Shields Gazette.
"I had personal problems. Sometimes it's tough. You have to decide between the problems and the work.
"Sometimes it's too difficult. Now it's finished, and next season I will be here. I'm looking forward to improving.
"We want the best for Newcastle United.
"This season we finished top 10, and maybe we will bring some players (in the transfer window).
"We will try to do well and finish in the top eight, or something like that. We will always try to improve."
Newcastle's 3-0 win over Cardiff City on Saturday was marred by a walkout of home fans midway through the second half in protest against Pardew's reign, the dismal form in the second half of the season and the way the club is being run by owner Mike Ashley.
And Coloccini has sympathy with the supporters' frustrations.
"We understand the fans," he added.
"We know that we didn't do well in the last two or three months.
"We have to accept that and be honest on the pitch. We have to always give the same – 100 per cent like we did (against Cardiff)."
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