Willi Kollo, born Willi Artur Kollodzieyski (* April 28, 1904 in Königsberg; † February 4, 1988 in West Berlin), was a German composer and author.
He was the son of the composer Walter Kollo and his wife Marie Kollo, née Preuß (1883-1954) and began his career at a young age as a close associate of his father. As a result, he wrote texts for his father's operettas at the age of twelve. Among other things, the two collaborated on the operetta ''Marietta'' which premiered at the Metropol Theater in Berlin in 1917. The titles "Was eine Frau im Frühling träumt" and "Warte, warte nur ein Weilchen" were taken from the work.
Willi Kollo later made a name for himself as an author of cabaret revues in Berlin in the late 1920s. From 1930 he also wrote screenplays and film music. After World War II, he moved from Berlin to Hamburg, returning to Berlin in 1955. He founded a music publishing company that also published his own chansons.

An advertising slogan of his company in the 1950s was:
Whatever the offspring drives,
whether rock , chacha, mambo writes:
Kollo stays!

He was the father of the tenor René Kollo and the agent for musical theater and music and stage publisher Marguerite Kollo.
Willi Kollo died of heart failure in Berlin in February 1988 at the age of 83. His grave is located at the state-owned cemetery Heerstraße in Berlin-Westend (grave location: 13-C-2).
On September 30, 2010, a memorial plaque to Walter and Willi Kollo was unveiled at Berlin's ''Admiralspalast'' for whose revue theater the Kollos worked.