Here is the full list of all 43 Mafia: Definitive Edition achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Collected 30 vehicles in the Garage
Found all Mystery Foxes
Lost the cops after accruing a five star police chase
Took Paulie to a Place of Disrepute
Reached 50mph while driving the Bolt Ace
Completed the Collection
Found all Pulp Magazines
Found all of the hidden cars
Found all copies of Gangsters Monthly
Found all 'Gangsters of the United States' cigarette cards
Found a hidden car
Performed a wheelie for 3 seconds
Lockpicked 5 cars on the streets of Lost Heaven and environs
Completed "The Death of Art"
Completed the game on Easy, Medium, or Hard difficulty
Completed "Moonlighting"
Completed "Just For Relaxation"
Resisted arrest by the Lost Heaven Police Department
Completed "Election Campaign"
Collected 15 vehicles in the Garage
Found a Mystery Fox
Completed "Crème de la Crème"
Completed "You Lucky ..."
Completed "Happy Birthday"
Completed "Bon Appétit"
Completed "Great Deal"
Completed "Visiting Rich People"
Completed "Omerta"
Completed "A Trip to the Country"
Completed "The Saint and the Sinner"
Completed "Better Get Used to It"
Found a copy of Gangsters Monthly
Completed "Sarah"
Completed "Fair Play"
Won the race
Completed "Ordinary Routine"
Completed "Molotov Party"
Found a Pulp Magazine
Found a 'Gangsters of the United States' cigarette card
Completed "Running Man"
Paid a fine to the Lost Heaven Police Department
Completed "An Offer You Can't Refuse"
Completed the game on Classic difficulty