For people who like lists of things, here is a list of all the wide releases (600+ theaters) of 2018. There were 161 of them, which is about average. Movies that opened small and eventually expanded are included, as are films (marked by an *) that are now in limited release but scheduled to go wide in January. Links are to my reviews, which are authoritative and final.
1/5 Insidious: The Last Key
1/12 The Commuter
1/12 Paddington 2
1/12 Proud Mary
1/19 12 Strong
1/19 Den of Thieves
1/19 Forever My Girl
1/26 Maze Runner: The Death Cure
2/2 Winchester
2/9 The 15:17 to Paris
2/9 Fifty Shades Freed
2/9 Peter Rabbit
2/16 Black Panther
2/16 Early Man
2/16 Samson
2/23 Annihilation
2/23 Every Day
2/23 Game Night
3/2 Death Wish
3/2 Red Sparrow
3/9 Gringo
3/9 The Hurricane Heist
3/9 Strangers: Prey at Night
3/9 A Wrinkle in Time
3/16 7 Days in Entebbe
3/16 I Can Only Imagine
3/16 Love, Simon
3/16 Tomb Raider
3/23 Isle of Dogs
3/23 Midnight Sun
3/23 Pacific Rim Uprising
3/23 Paul, Apostle of Christ
3/23 Sherlock Gnomes
3/23 Unsane
3/29 Ready Player One
3/30 Acrimony
3/30 God’s Not Dead: A Light in Darkness
4/6 Blockers
4/6 Chappaquiddick
4/6 The Miracle Season
4/6 A Quiet Place
4/11 Beirut
4/13 Rampage
4/13 Sgt. Stubby: An American Hero
4/13 Truth or Dare
4/20 I Feel Pretty
4/20 Super Troopers 2
4/20 Traffik
4/27 Avengers: Infinity War
5/4 Bad Samaritan
5/4 Overboard
5/4 Tully
5/11 Breaking In
5/11 Life of the Party
5/18 Book Club
5/18 Deadpool 2
5/18 Show Dogs
5/25 Solo: A Star Wars Story
6/1 Action Point
6/1 Adrift
6/1 Upgrade
6/8 Hereditary
6/8 Hotel Artemis
6/8 Ocean’s Eight
6/8 Won’t You Be My Neighbor?
6/13 Superfly
6/15 Incredibles 2
6/15 Tag
6/22 Jurassic World: Fallen Kingdom
6/29 Sicario: Day of the Soldado
6/29 Uncle Drew
7/4 The First Purge
7/6 Ant-Man and the Wasp
7/6 Sorry to Bother You
7/13 Eighth Grade
7/13 Hotel Transylvania 3: Summer Vacation
7/13 Skyscraper
7/20 The Equalizer 2
7/20 Mamma Mia! Here We Go Again
7/20 Unfriended: Dark Web
7/27 Mission: Impossible — Fallout
7/27 Teen Titans Go! To the Movies
8/3 Christopher Robin
8/3 The Darkest Minds
8/3 Death of a Nation
8/3 The Spy Who Dumped Me
8/8 Dog Days
8/10 BlacKkKlansman
8/10 The Meg
8/10 Slender Man
8/15 Crazy Rich Asians
8/17 Alpha
8/17 Mile 22
8/24 A.X.L.
8/24 Beautifully Broken
8/24 The Happytime Murders
8/24 Searching
8/31 Kin
8/31 Operation Finale
9/7 God Bless the Broken Road
9/7 The Nun
9/7 Peppermint
9/14 The Predator
9/14 A Simple Favor
9/14 Unbroken: Path to Redemption
9/14 White Boy Rick
9/21 The House with a Clock in Its Walls
9/21 Life Itself
9/21 The Sisters Brothers
9/21 Fahrenheit 9/11
9/28 Hell Fest
9/28 Little Women
9/28 Night School
9/28 The Old Man & the Gun
9/28 Smallfoot
10/5 The Hate U Give
10/5 Shine
10/5 A Star Is Born
10/5 Venom
10/12 Bad Times at the El Royale
10/12 Beautiful Boy
10/12 First Man
10/12 Goosebumps 2: Haunted Halloween
10/12 Gosnell: The Trial of America’s Biggest Serial Killer
10/19 Halloween
10/19 Mid90s
10/26 Hunter Killer
10/26 Indivisible
10/26 London Fields
11/2 Bohemian Rhapsody
11/2 Boy Erased
11/2 Nobody’s Fool
11/2 The Nutcracker and the Four Realms
11/2 A Private War
11/7 The Front Runner
11/9 Girl in the Spider’s Web
11/9 The Grinch
11/9 Overlord
11/16 Fantastic Beasts: The Crimes of Grindelwald
11/16 Green Book
11/16 Instant Family
11/16 Widows
11/21 Creed II
11/21 Ralph Breaks the Internet
11/21 Robin Hood
11/23 The Favourite
11/30 The Possession of Hannah Grace
12/7 Mary Queen of Scots
12/14 Mortal Engines
12/14 The Mule
12/14 Spider-Man: Into the Spider-Verse
12/14 If Beale Street Could Talk*
12/19 Mary Poppins Returns
12/21 Aquaman
12/21 Bumblebee
12/21 Second Act
12/21 Welcome to Marwen
12/25 Holmes & Watson
12/25 On the Basis of Sex*
12/25 Vice
12/25 Destroyer*