July 2009, updated October 2009


Personal experience of smoking sections in bold. If anyone has had experience of being able to smoke at a ballpark officially designated as non-smoking, let me know.
Chase Field is designated as a non-smoking facility. For those guest wanting to smoke, designated areas outside the facility are located at areas:
Outside of Gate A (north plaza)
Outside of Gate J (east)
Outside of Gate K (northeast)
As these locations are outside the ballpark, you will need your ticket stub and "re-entry" card to re-enter.
Turner Field is primarily a smoke-free facility. Smoking is permitted in designated areas only. As shown on the ballpark directory and maps, these areas include certain entryways, stairwells and landings. Smoking is prohibited in the seating bowl, concourses, Plaza, restrooms and in all premium seating areas.
For the health and comfort of others, smoking is prohibited in all areas of the ballpark except along the Upper Level Concourse, the Eutaw Street corridor, and portions of the Bullpen Picnic Grove. Fans who fail to comply with this policy, after appropriate warning, may be subject to ejection from the ballpark.

When I asked someone at the concessions on the upper concourse where the smoking section was, she smiled at told me, "You're standing in it!"
Smoking is not allowed in Fenway Park.
Exiting and re-entering the Park is not permitted at any gate.

Thanks to Adam Westlund who pointed out that smoking is possible outside the ballpark on Yawkey Way.

Update: Marisa Biondi, an employee at Fenway Park, emailed me and pointed out that as of August 2009, smoking is no longer allowed on Yawkey Way, and that "the ONLY place to smoke during games is in the patio of Who's On First, a bar on Yawkey way. You must have your ticket to enter and exit the bar."
Smoking is strictly prohibited in Wrigley Field.
Smoking is not allowed inside U.S. Cellular Field pursuant to Smoke-Free Illinois Act 95-0017. Smoking anywhere inside U.S. Cellular Field, including the ramps, is prohibited. Guests wishing to smoke exit the ballpark at the base of the ramps at Gate 5 (third-base line). Please notify a staff member of any violation of this policy.
Ohio voters passed issue Number 5, on Nov. 7, 2006, which calls for a smoking ban in public facilities and places of employment under Ohio Revised Code Chapter 3794. Thus, Great American Ball Park has been designated as a completely non-smoking facility. Guests are not permitted to smoke inside of Great American Ball Park and are not permitted to exit and re-enter for the purpose of smoking. Violators may be subject to ejection and potential fines.
In accordance with the laws of the State of Ohio, Progressive Field is a nonsmoking facility.

Reentry Into The Ballpark
Guests may not exit and reenter Progressive Field using the same ticket. In case of an emergency, a pass out slip may be obtained at the gate.
Denver City Ordinance 655 prohibits smoking in Coors Field except in designated smoking areas. All seating areas are classified as non-smoking. Designated smoking areas are marked by yellow lines and are located as follows:
Inside the 22nd Street entrance (Gate B) behind section 112
Inside the 21st and Blake Street entrance (Gate C) behind section 122
Inside the 20th and Blake Street entrance (Gate D) behind section 130
Backside of the concourse behind section 148

Not listed on their Web site, but there is - or at least there was in June '08 - a smoking section on the concourse behind the bleachers. Of the fifteen current ballparks I've been to, this is the only smoking section where one can smoke and have a view of home plate at the same time.
Smoking is prohibited in all seating areas, restrooms, concession stands/areas and concourses of Comerica Park. Designated smoking areas are in the open-air areas of ramps behind sections 125 and 140, the concourse area behind section 101-102, the open-air area behind sections 325 and 340 and the rooftop areas behinds section 215-216. Smoking is also allowed in the Camacho Cigar Bar, (Tiger Club access is needed for entry to the Camacho Cigar Bar).
Smoking is not permitted in the seating areas, restrooms, concourse or any area of the Club Level of the Land Shark Stadium. Smoking is permitted on the ramps of each level in the designated areas.
Smoking at Minute Maid Park is allowed only in designated smoking areas. Fans seated in the Club, Suite and Upper Concourse levels may go to any of the roof terraces or ramps. Ask any ballpark personnel for the exact locations of these areas. Fans in the Main Concourse may go to the exterior smoking area behind Section 120 or leave the building at the Right Field, South Home Plate, Center Field or Union Station gates. Fans must have their ticket punched before exiting the building and present their ticket stub upon re-entry. Smoking is strictly prohibited on any concourse or in any of the stairwells.
Smoking is not permitted anywhere inside the structure of Kauffman Stadium. Designated smoking areas are located along the perimeter fence line between Gates B & D and along the perimeter fence line between Gates A & E. Smoking is allowed in these designated areas only.
For the health and comfort of others, smoking will not be permitted in the seating areas, suites, concourses and restrooms. Smoking will be allowed in designated areas such as the ramps and the Plaza Courtyard area. Fans who fail to comply with this policy may be subject to ejection from the ballpark.
Dodger Stadium is a smoke-free stadium. All smokers will have to exit the stadium to smoke. Security personnel will have to sign guests out at the entrance gates.
In an effort to accommodate all guests, smoking is allowed only in designated areas of Miller Park. Designated smoking areas for guests are located on identified outer plaza areas on the Field Level, behind sections 106 and 127, Friday's outdoor patio, and the Left Field Loge Bar. Smoking is also permissible in The Beer Garden, located in the right field corner of the Terrace Level concourse. Smoking is prohibited in the entire seating bowl of Miller Park as well as all concourses, suites and restrooms.

The Beer Garden area is awesome. Like a pub where you can smoke and watch the game on loads of TVs.
In accordance with the Minnesota Clean Indoor Air Act, there is no smoking in the Metrodome. Smoking is permitted in the outer gate areas between the turnstiles and revolving doors only.
Smoking at Citi Field is prohibited. Any ticketholder violating this prohibition will be subject to ejection.

When I visited in June '09, I found a smoking section does exist behind all the food and drink places beyond centerfield.
Smoking is prohibited in Yankee Stadium. In consideration for the comfort of all guests, the Yankees ask for your cooperation. There are no designated smoking areas inside Yankee Stadium, and re-entry is prohibited. The smoking policy is strictly enforced, and violators will be ejected from Yankee Stadium immediately.

A fine example of why not having a smoking section is a bad idea: on more than one occasion, I've seen smokers powering through a cigarette while they urinated.
In accordance with City of Oakland Municipal Code 8.30.090, the Oakland A's are pleased to announce that all A's events are Smoke Free. There are two (2) designated smoking areas located at Sec. 205 and Sec. 229 on the Club Concourse.
By City of Philadelphia ordinance, smoking is only permitted in designated areas (First Base Gate, Third Base Gate, Left Field Gate and the East Suite and Club Entrance). Violators may be ejected and/or have their season tickets revoked.
In consideration of the health and comfort of others, smoking is not permitted anywhere in PNC Park. The Club reserves the right to eject any person violating this policy.
Please note that as is the policy for all ticket holders, there is no re-entry once a guest has exited PNC Park.

I'm not proud to say that I've broken the rules in PNC Park. I saw a guy sneakily smoking in the top row on the third base line and joined him. Sorry, Pittsburgh.
PETCO Park is a smoke-free facility. Guests who wish to smoke at a PETCO Park event are required to utilize the designated smoking areas outside the ballpark. Guests wishing to exit the ballpark and return to the same event must receive a re-entry stamp from gate personnel.
In accordance with San Francisco City Ordinance, AT&T Park is a SMOKE-FREE facility with no smoking areas. Smoking is not permitted anywhere in the ballpark. The ballpark smoking policy is subject to change at the discretion of Giants management.

I saw two women smoking behind the big scoreboard thing. There weren't many people around, so it was a good place to have a crafty one.
In compliance with the Washington Clean Air Act, Safeco Field is a no smoking (including chewing tobacco) facility. Smoking is not permitted in any location inside Safeco Field or within 25 feet of all entrances, windows and ventilation intakes. Smoking is permitted only in designated areas 25 feet away from the Home Plate, Right Field, Left Field and Center Field Gates, as well as the north end of the Parking Plaza. Guests exiting the ballpark to smoke must have their ticket scanned for re-entry by a Gate Host prior to exiting.
Busch Stadium is a smoke-free facility.

Exit/Re-Entry turnstiles will be set up at Gates 2, 4 and 6 to allow fans access in and out of the stadium if they wish to smoke. Fans will get their hand stamped as they exit the stadium. Guests must show ticket upon re-entry. Inspection policy will also be enforced.

Employees wishing to smoke may do so outside of the stadium prior to entering the building for work or while on break. The smoking area for employees will be south of the employee entrance next to the stadium. This area will not be specifically designated for employees as fans may be in this area as well. Please remember that even though you are on your break, our fans may still ask you questions or seek information. Please act professionally at all times and set an example by disposing of your cigarettes in the proper ash trays provided.
Tropicana Field is a smoke-free facility. Smoking is prohibited anywhere inside Tropicana Field. Guests are permitted to smoke inside the fenced areas outside the building at Gates 2, 3, 5, 6, and 7; or outside on the ramps at Gates 2, 3, 5 and 6.
Smoking is not permitted in the seating bowl, the Lexus Club Level, suites area, or on the Concourse behind Section 44 - past the Visitors Bullpen (Coca-Cola Sports Park), but guests may smoke at designated areas near the outer perimeter of the first level, and upper the concourse [sic].
Since January 2006, Rogers Centre has been a smoke-free environment, in compliance with the Province of Ontario's Smoke-Free Ontario Act. Smoking is not permitted at any level in the building. Security issues preclude us from allowing guests back into the building if they choose to exit. Those fans leaving the facility to smoke, will not be permitted re-entry to the stadium.
The ballpark is a completely non-smoking facility. Guests wishing to smoke must exit at either the First Base Gate or the Third Base Gate. Guests wishing to exit the ballpark to smoke must present a valid ticket and receive a wristband before exiting the ballpark. Guests wishing to reenter the ballpark must return with a valid ticket and assigned wristband. Guests may not exit and reenter the ballpark using only an admission ticket for any reason.