John Charles Kenneth Gärdestad (9 May 1948 – 3 March 2018) was a Swedish songwriter, best known for writing lyrics for the songs of his brother, Ted Gärdestad.
He won Melodifestivalen 1979 as a songwriter for "Satellit" performed by his brother.
The song went on to Eurovision the same year, where it placed 17th.
Gärdestad was also an architect, affiliated to the private Kunskapsskolan, where he designed the interior of several of its high schools.
Gärdestad published the biography Jag vill ha en egen måne in 2005.
In later years he became a mental health activist, and created the "Ted Gärdestad Stipend", a prize awarded to amateur singers and songwriter.