It's Arbor Day, Charlie Brown is the 15th prime-time animated television special based on Charles M. Schulz's comic strip Peanuts. The subject of the special is Arbor Day, a secular holiday devoted to planting trees. It's Arbor Day, Charlie Brown premiered on the CBS network on March 16, 1976, which is near the dates in which most U.S. states observe Arbor Day. This is the first special to feature the character Rerun van Pelt (younger brother to Linus and Lucy), who had debuted in the Peanuts comic strip in March 1973.

The musical score features the final compositions and recorded performances of jazz pianist and composer Vince Guaraldi, whose contributions to Peanuts include the theme "Linus and Lucy". Guaraldi died suddenly on February 6, 1976—a little over a month before the special's premiere.

It's Arbor Day, Charlie Brown was distributed as a bonus feature on Paramount Home Video's 2003 DVD-Video release of It's the Easter Beagle, Charlie Brown (1974). A remastered version was published on DVD by Warner Home Video in 2008, and in the DVD box set Peanuts 1970's Collection, Vol. 2 in 2010.