CagneyThe big hype tonight is the fish-out-of-water fight between unbeaten boxer Floyd Mayweather Jr. vs. Conor McGregor (pay-per-view, 9 p.m.), the mixed martial arts hero. The last time anybody tried this, the MMA guy died. Anyway, even the loser or his designees, makes $35 million.

Networks get involved with the undercard at least with Preliminary Bouts (Fox, 7 p.m.).

And for more conventional boxing there’s Miguel Cotto vs. Yoshiko Kamegai (HBO, 9:45 p.m.).

You want tough guys, though? It’s Cagney all day on Turner Classic Movies with James Cagney in “Blond Crazy” (6 a.m.), “The Crowd Roars” (7:30 a.m.), “Jimmy the Gent” (8:45 a.m.), “The Strawberry Blonde” (10 a.m.), “Captains of the Clouds” (11:45 a.m.), “Yankee Doodle Dandy” (2 p.m.), “The Bride Came C.O.D.” (4:15 p.m.), “Shake Hands with the Devil” (6 p.m.), “White Heat” (8 p.m.), “The Roaring Twenties” (10 p.m.), “Love Me or Leave Me” (midnight), “The Gallant Hours” (2:15 a.m.) and “The Mayor of Hell” (4:30 a.m.).

Preseason football has Chargers at Rams (CBS, 8 p.m.). Wait, after 21 years of having none, Los Angeles has two NFL franchises?

The fourth season start of “Halt and Catch Fire” (AMC, 9 p.m.) has been particularly good; it’s not too late to check in tonight as Cameron promotes her game at an industry conference.

“Jackie” (HBO, 8 p.m.), with Natalie Portman as the widowed First Lady, makes its premium cable debut.

Rehashing old tabloid stories seems to be a thing these days. One of the latest is “The Disappearance of Natalee Holloway” (Oxygen, 9 p.m.).

It’s a tale that could fit on the new “Mysteries of the Missing” (Science Channel, 10 p.m.), which instead begins at one of CNN’s old obsessions, the disappearance of Malaysia Airlines Flight 370. Terry O’Quinn is host.

On the made-for-TV movie “Sun, Sand & Romance” (Hallmark, 9 p.m.), a publishing executive’s boyfriend bails on a beach trip, so she reconnects with an old friend. Tricia Helfer stars with Paul Campbell and Scott Elrod.

“The Dead Files” (Travel, 10 p.m.) goes to upstate New York.

“Planet Earth: Wild West” (BBC America, 9 p.m.) continues to explore the high country in the American West.

A retired Air Force sergeant is paired with a German Shepherd on “Rescue Dog to Super Dog” (Animal Planet, 10 p.m.).

“Ghost Adventures: Artifacts” (Travel, 9 p.m.) gets pretty gruesome as Zak acquires a cauldron used by serial killer Ed Gein to cook body parts.

Like everyone else, “The Kitty Kelley Files” (Reelz, 9 p.m.) profiles Princess Diana.

College football starts tentatively with a handful of games. They include Oregon State at Colorado State (CBS Sports, 2:30 p.m.), Portland State at BYU (ESPN, 3 p.m.), South Florida at San Jose State (CBS Sports, 7:30 p.m.) and Rice at Stanford (ESPN, 10 p.m.) in Sydney, Australia.

Baseball includes Seattle at Yankees (MLB, 1 p.m.), Mets at Washington (Fox Sports 1, 4 p.m.), Kansas City at Cleveland (Fox Sports 1, 7 p.m.) and Houston at Angels (MLB, 10 p.m.).

In the Little League finale, it’s Mexico vs. Japan (ABC, 12:30 p.m.) in the international title game and Greenville, N.C., vs. Lufkin, Texas (ABC, 3:30 p.m.) in the U.S. title game.

In golf there is third round play in the Northern Trust (Golf, 1 p.m.; CBS, 3 p.m.).

Tennis has its finals in the Connecticut Open (ESPN2, 3 p.m.) and the Winston-Salem Open (ESPN2, 5 p.m.).

The Foals and Alejandro Escovedo play “Austin City Limits” (PBS, 11 p.m., check local listings).

The 42nd season premiere , with Ryan Gosling and Jay Z, is not for another month. In the meantime, here’s a replay of last season’s  Aziz Ansari-hosted “Saturday Night Live” (NBC, 11:30 p.m.) with Big Sean.