Abbot Genser/HBO

Two sweeping new HBO dramas, “Boardwalk Empire” and “Game of Thrones,” will challenge AMC’s three-time winner “Mad Men” for the title of best drama in the 63rd annual Primetime Emmy Awards this year.

The nominations, announced on Thursday by the Academy of Television Arts & Sciences, also placed the outgoing DirecTV/NBC show “Friday Night Lights” into contention for the drama award for the first time, alongside Showtime’s “Dexter” and “The Good Wife” on CBS.

Of all the programs on television, the HBO mini-series “Mildred Pierce” was the academy’s most-nominated this year, with 21. “Mad Men” picked up the most nominations of any single drama, 19, up from 17 last year, while “Boardwalk Empire” picked up 18.

Terence Winter, the creator and executive producer of “Boardwalk Empire,” volunteered no predictions about his show’s chances. Instead, he said in an interview, “I am just thrilled to be able to amortize my tuxedo for yet another year.”

Kyra Sedgwick, who won for best lead actress in a drama for “The Closer” on TNT last year, was snubbed this year; among the nominees are Julianna Margulies of “The Good Wife,” Connie Britton of “Friday Night Lights,” Elisabeth Moss of “Mad Men” and Mireille Enos of “The Killing,” also on AMC. For Ms. Enos, an alumna of HBO’s widely praised “Big Love” who plays the homicide detective Sarah Linden on “The Killing,” the nomination is her first shot at an Emmy, television’s top prize.

“The work itself is the goal,” Ms. Enos said on Thursday from a movie set in London, “but when you get a part as rich as Sarah, there is the thought at the back of your mind that this is a part that could potentially bring you to the Emmys, and that’s an exciting possibility, so to see that happen is really thrilling.”

There was one new entrant in the best actor category: Timothy Olyphant of FX’s “Justified,” who joined, among others, Jon Hamm of “Mad Men” and Steve Buscemi of “Boardwalk Empire.” The category’s three-time winner, Bryan Cranston, was not nominated because his show, “Breaking Bad,” was ineligible. Its next eligible season starts this month.

Michael Yarish/AMC

The Fox network will televise the Emmy Awards on Sept. 18. It is a reflection of the waning influence of network television — and of the dearth of new hit shows this past season — that “The Good Wife” was the only purely network-distributed drama to be nominated on Thursday. “Friday Night Lights” is distributed jointly by DirecTV and NBC.

In the best comedy category, the three-year-old CBS sitcom “The Big Bang Theory” was nominated for the first time, representing a major victory for its producer, Chuck Lorre, as well as for its studio, Warner Brothers, which campaigned aggressively for the nod. “Big Bang” will challenge last year’s winner, ABC’s “Modern Family,” as well as Fox’s “Glee” and three NBC sitcoms, “The Office,” “30 Rock” and “Parks and Recreation.”

In recent years the Emmys have favored single-camera comedies like “30 Rock” over multicamera, laugh-track comedies like “Big Bang,” making the nomination significant.

Jim Parsons and Johnny Galecki of “Big Bang” were each nominated for lead actor in a comedy series, joining Steve Carell of “The Office,” who has been nominated every full year since the show had its debut in 2005 but has never won; this is his last year on the show. Also nominated in that category was Louis C. K. of FX’s “Louie,” who said in an interview, “I’d love to be able to say that I’m just a pure artist and that awards are meaningless, but getting the nomination is cool.”

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In the category for lead actress in a comedy series, last year’s winner, Edie Falco of Showtime’s “Nurse Jackie,” was joined by, among others, a presenter of the nominations, Melissa McCarthy of CBS’s “Mike & Molly,” a first-year sitcom.

Notably, each of the parents on “Modern Family” was nominated as a supporting actor or actress — six in all — including Ed O’Neill, who plays the family patriarch and was overlooked last year.

In the lead actress in a comedy series last year’s winner, Edie Falco of Showtime’s “Nurse Jackie,” was joined by Tina Fey of NBC’s “30 Rock,” Amy Poehler of NBC’s “Parks and Recreation,” Martha Plimpton of Fox’s “Raising Hope,” Melissa McCarthy of CBS’s “Mike & Molly,” and Laura Linney of Showtime’s “The Big C.”

For the 11th consecutive year HBO received the most nominations of any network or cable channel, largely thanks to its mini-series and made-for-television movies. It earned 104 nominations, up from 101 last year.

In the mini-series category, HBO’s “Mildred Pierce,” “Cinema Verite” and “Too Big to Fail” were joined by PBS’s “Downton Abbey,” “The Kennedys” on ReelzChannel and “The Pillars of the Earth” on Starz. “The Kennedys,” the subject of controversy last year, was canceled by the History Channel in January, allowing the much smaller ReelzChannel to pick it up.

“The supporting actor/comedy category looks like some sort of weird psychodrama, or like one of those writing categories with four episodes of ‘Mad Men.'” — Mike Hale, a Times critic, on the comedy nominees.

For the 11th year in a row HBO received the most nominations of any network or cable channel, largely thanks to its mini-series and made-for-television movies. It got 104 nominations, up from 101 last year.

The Emmy voters appeared to signal a changing of the guard in late-night television, as neither “The Tonight Show With Jay Leno” on NBC or CBS’s “Late Show With David Letterman” were nominated in the outstanding variety, music or comedy category, nor for best writing. Instead, TBS’s “Conan” and NBC’s “Late Night With Jimmy Fallon” joined the regulars in the series category, Comedy Central’s “Daily Show With Jon Stewart” and “The Colbert Report,” HBO’s “Real Time With Bill Maher” and NBC’s “Saturday Night Live.”

Conan O’Brien, who moved to TBS from NBC last year, also picked up a writing nomination.

Matt LeBlanc, a three-time nominee for NBC’s “Friends,” was celebrating his nomination in the best actor in a comedy category for his performance in “Episodes,” a Showtime series that casts him as an exaggerated, self-centered version of himself. Asked if he was getting tired of the kudos, Mr. LeBlanc responded: “Uh, no. If I remember the experience correctly, getting nominated and winning are two very different things.”

Members of the Academy of Television Arts & Sciences select the nominees. Below is a list of nominees in the top categories. The complete list can be found here. A slide show of the nominees can be found here.

Bill Carter contributed reporting.

Comedy Series

The Big Bang Theory

Glee

Modern Family

The Office

Parks and Recreation

30 Rock

Drama Series

Boardwalk Empire

Dexter

Friday Night Lights

Game of Thrones

The Good Wife

Mad Men

Lead Actress in a Comedy

Laura Linney, The Big C

Edie Falco, Nurse Jackie

Amy Poehler, Parks and Recreation

Melissa McCarthy, Mike & Molly

Martha Plimpton, Raising Hope

Tina Fey, 30 Rock

Lead Actor in a Comedy

Matt LeBlanc, Episodes

Jim Parsons, The Big Bang Theory

Steve Carell, The Office

Johnny Galecki, The Big Bang Theory

Louis C.K., Louie

Alec Baldwin, 30 Rock

Lead Actor in a Drama

Steve Buscemi, Boardwalk Empire

Michael C. Hall, Dexter

Kyle Chandler, Friday Night Lights

Jon Hamm, Mad Men

Hugh Laurie, House

Timothy Olyphant, Justified

Lead Actress in a Drama

Elisabeth Moss, Mad Men

Connie Britton, Friday Night Lights

Mariska Hargitay, Law & Order: SVU

Mireille Enos, The Killing

Julianna Margulies, The Good Wife

Kathy Bates, Harry’s Law

Supporting Actor in a Comedy

Jon Cryer, Two and a Half Men

Chris Colfer, Glee

Jesse Tyler Ferguson, Modern Family

Ed O’Neill, Modern Family

Eric Stonestreet, Modern Family

Ty Burrell, Modern Family

Supporting Actor in a Drama

John Slattery, Mad Men

Andre Braugher, Men of a Certain Age

Walton Goggins, Justified

Peter Dinklage, Game of Thrones

Josh Charles, The Good Wife

Alan Cumming, The Good Wife

Supporting Actress in a Comedy

Jane Lynch, Glee

Betty White, Hot in Cleveland

Julie Bowen, Modern Family

Kristen Wiig, Saturday Night Live

Jane Krakowski, 30 Rock

Sofia Vergara, Modern Family

Supporting Actress in a Drama

Kelly Macdonald, Boardwalk Empire

Christina Hendricks, Mad Men

Michelle Forbes, The Killing

Archie Panjabi, The Good Wife

Margo Martindale, Justified

Mini-series or Made-for-Television Movie

Cinema Verite

Downton Abbey

The Kennedys

Mildred Pierce

The Pillars Of The Earth

Too Big To Fail

Variety, Music or Comedy Series

The Colbert Report

Conan

The Daily Show With Jon Stewart

Late Night With Jimmy Fallon

Real Time With Bill Maher

Saturday Night Live

Lead Actor in a Mini-Series or movie

Edgar Ramirez, Carlos

Greg Kinnear, The Kennedys

Barry Pepper, The Kennedys

Idris Elba, Luther

Laurence Fishburne, Thurgood

William Hurt, Too Big To Fail

Lead Actress in a Mini-Series or movie

Diane Lane, Cinema Verite

Elizabeth McGovern, Downton Abbey

Kate Winslet, Mildred Pierce

Taraji P. Henson, Taken From Me: The Tiffany Rubin Story

Jean Marsh, Upstairs Downstairs

Reality Program

Antiques Roadshow

Deadliest Catch

Hoarders

Kathy Griffin: My Life On The D-List

MythBusters

Undercover Boss

Reality Competition

The Amazing Race

American Idol

Dancing With The Stars

Project Runway

So You Think You Can Dance

Top Chef

Host of a Reality Program or Competition

Phil Keoghan, The Amazing Race

Ryan Seacrest, American Idol

Tom Bergeron, Dancing With The Stars

Cat Deeley, So You Think You Can Dance

Jeff Probst, Survivor