No, Trump barely won in 2020 with about 33% of the vote.
View full results and an interactive map for the 2020 Iowa caucuses.
www.cnn.com
In 2016 when Trump was still an unknown as President that he came in second with 24.3% of the vote to Ted Cruz's 27.6%.
From the Des Moines Register:
"Donald Trump
won the 2024 Iowa Caucuses in a landslide, securing an unprecedented victory over rivals who spent the better part of a year unsuccessfully urging Iowans to move on from a former president beset by legal challenges and the baggage of a failed 2020 run.
Rather than unite around a challenger, Iowa Republicans largely embraced Trump, delivering him the strongest win by a presidential candidate in the Republican caucuses’ 48-year history. . ."