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