Sources please :D
http://www.beatlesbible.com/1966/11/09/john-lennon-meets-yoko-ono/ http://en.wikipedia.org/wiki/John_Lennon Apparently, just turned 26
He was born October 9, 1940. He met Yoko Ono on November 9, 1966. So, @josie is correct. John Lennon was 26 when he met her. Yoko Ono was born February 18, 1933.
Sources and this.
Wow, YO is going to turn the big eight zero next February. Hopefully time has taken at least some of the edge off of her vocal chords. ;-)