The Model 3 is the third different model to win the monthly sales ranking. The Dacia Sandero was tops in January.
The Peugeot 208 was No. 2 in March despite an 18 percent decline.
Last month the 208 passed the Sandero to finish the first quarter as Europe's No. 1-seller, according to figures from Dataforce.
The Sandero, which had a sales increase of 29 percent on March 2021, was one of just two models in the top 10 for last month to record a gain. The other was the Hyundai Tucson (+1.8 percent).
The Peugeot 208 was No. 2 overall for the third consecutive month.
Looking at the rest of the top 50 for Europe for March, several of the big winners were SUVs: the Kia Sportage, Toyota C-HR and Opel/Vauxhall Mokka.
After three months the big winners included the Hyundai Kona, Kia Niro and Cupra Formentor.