Three years after the Sir Robert Woodard Academy was told it 'requires improvement', academy principal Kieran Scanlon said he is 'delighted' that the school is 'finally getting the recognition it deserves'.
Mr Scanlon also paid tribute to the school's late chair of governors.
He said: "I’m sad that our recently deceased chair of governors, David Simmons, wasn’t here on the day.
"I take some comfort from the fact that he knew the school has been operating at a very good level for a while now.
"We will take every opportunity to continue to go from strength to strength. SRWA is a great place to be."
A school spokesperson said the good news is 'momentous' for the school, 'the whole of Lancing and much of Shoreham and Worthing'.
They added: "All at The Sir Robert Woodard Academy are are delighted to have confirmation of what those on the inside have known for some time - this is a 'Good' school!"
Inspectors praised the high aspirations and ambitious culture at the school.
The report noted that, from Year 7 through to the sixth form, pupils 'learn to think ambitiously about their futures', adding: "They are proud of their achievements and eager to meet their teachers’ high expectations of them."
Inspectors also praised the broad curriculum, strong careers provision and sixth form, as well as the wide range of extra curricular and creative opportunities.
"Pupils from Year 7 to sixth form enjoy a range of practical, sporting, creative and academic clubs," the report stated.
"The arts are particularly valued in the school and participation in theatre, dance and musical events is high.
"The school is a calm and orderly place for pupils to learn. Pupils treat each other with respect in lessons and during social times.
"Pupils feel safe at school and know who to go to if they have a problem.
"This includes effective responses to any bullying.
"They trust their teachers because they are confident that they will receive support and guidance when they need it."
Inspectors were impressed with the 'effective' arrangements for safeguarding, as well as the support for students, with special educational needs and/or disabilities (SEND).
However, the school was told about two areas, where improvements could still be made.
The report stated: "Sometimes, teachers move the learning on before all pupils have secured the prior knowledge they need. As a result, some pupils are then unable to access the
next stage in learning well enough and get left behind.
"Teachers should use timely and systematic approaches to check that pupils are learning the curriculum as it is being taught.
"Despite leaders’ work to improve attendance, rates of persistent absence are higher than they should be. Leaders should continue with their work to tackle this issue so that pupils attend school more regularly."