Jude Hunton will take up the vacant role in September when the school year starts.
This follows the announcement the current principal Emma Day will be moving to a job in Qatar with her family.
Mrs Day was appointed after the school, part of the David Ross Education Trust, was reported ‘Requires Improvement’ in an Ofsted inspection in 2017.
The Trust has stated Mr Hunton is already working closely with Mrs Day on 'detailed planning for a full-school return in September'.
Mr Hunton, who is currently Vice Principal at another DRET school, has spent over 15 years in leadership roles, including at an Ofsted-graded Outstanding school in Rugby, Ashlawn School, where he led on teaching and learning and curriculum development.
Prior to this he worked at Nicholas Chamberlaine School in Warwickshire, supporting the school during its turnaround. He brings with him an extensive network of expertise, and is the founder of ResearchEd Rugby, a national education conference which is attended by over 450 educators and 50 speakers every year.
Commenting on his new appointment, he said: ‘It's an enormous privilege to lead Skegness Grammar School.
"Helping staff and students grow inspires me. I'm hugely excited, and humbled, to take responsibility for the education of so many incredibly bright and talented young people.
"My message for the SGS community is: I want us to aspire to the highest standards, to value personal responsibility, and to accept a duty to support each other in our journey to become our best selves."
Deputy CEO of DRET, Mark Niels, said: "We are extremely excited about this appointment - Jude is exactly the right fit for this school, someone with a background in a very high performing, outstanding school, and also someone who understands the challenges that the school faces.
"Jude is someone who is driven by a moral purpose to ensure that children from Skegness get a spectacular education.
"Coastal areas have their own unique set of challenges and this appointment shows our commitment that Lincolnshire should not be left behind."