The 27-year-old will go straight into the Tractor Boys squad for Saturday's trip to Reading after being deemed surplus to requirements by Rams head coach Steve McClaren.
Sammon began his career in Ireland before moving to Kilmarnock in 2008 where he made 65 appearances, scoring 17 goals.
It was in Scotland where he caught the attention of then Premier League side Wigan, who brought him to the DW Stadium for an undisclosed fee.
However he only managed to score one goal in 32 appearances for the Latics before linking up with Derby in 2012.
"Conor's first-team chances were limited last season," Steve McClaren told the official club website.
"Especially with Chris Martin in superb form.
"Moving on loan to Ipswich presents him with a strong possibility of playing first-team football."