First recorded by Marian Montgomery (1964).
Also recorded by O.C. Smith (1964).
Hit version by Frank Sinatra (US #4/MOR #1/R&B #25/UK #44 1966).
From the wiki: “‘That’s Life’ was written by Dean Kay and Kelly Gordon, and was first recorded in 1964 by Marion Montgomery. The most famous version is by Frank Sinatra, released on his 1966 album of the same name. Sinatra recorded the song after hearing an earlier cover of it by O.C. Smith (who recorded his version shortly after leaving Count Basie’s orchestra).”
O.C. Smith, “That’s Life” (1964):
Frank Sinatra, “That’s Life” (1966):