Smart received a flagrant foul and automatic ejection for the shove, which took place with 7:06 remaining in the third quarter of Philadelphia's 118-115 home victory over Boston on Wednesday.
Cameroonian center Embiid was sent sprawling to the court in the encounter but finished with game highs of 37 points and 22 rebounds for the 76ers.
Philadelphia improved to 47-25, third in the Eastern Conference, while dropping the Celtics to 43-29, fifth in the East and four games behind the Sixers.
The fine was based in part on Smart's repeated acts of unsportsmanlike conduct during NBA games, including two prior incidents this season that resulted in fines.
The NBA fined Smart $35,000 in January for being involved in an altercation with Atlanta forward DeAndre Bembry, the league saying it punished Smart for "aggressively pursuing an opponent in an attempt to escalate a physical altercation and failing to leave the court in a timely manner following his ejection."