First recorded by Bing Crosby (US #12 1946).
Other popular versions by Ethel Merman & Ray Middleton (1946), Frank Sinatra (US# 2 1946), Perry Como (US #4 1946)
From the wiki: “‘They Say It’s Wonderful’ was written by Irving Berlin for the musical Annie Get Your Gun (1946), where it was introduced on Broadway by Ethel Merman and Ray Middleton. The song was first recorded and released on a 78 rpm by Bing Crosby in 1946, a version that say modest chart success. Merman and Middleton released a recorded ‘cast’ version later in 1946. Frank Sinatra and Perry Como both charted in 1946 with covers of ‘They Say It’s Wonderful’.
“In 1979, Merman recorded a ‘camp’ version for The Ethel Merman Disco Album but it was not released until issued as a bonus track on the CD reissue in 2002.”
Ethel Merman & Ray Middleton, “They Say It’s Wonderful” (1946):
Frank Sinatra, “They Say It’s Wonderful” (1946):
https://youtu.be/pMZ47sUAwyU
Perry Como, “They Say It’s Wonderful” (1946):
https://youtu.be/v7mASlTLXVg