SPRING
 
St. Patrick's Parade and Corktown Race
The annual Corktown St. Patrick's Parade, sponsored by the United Irish Societies every year on the Sunday before St. Patrick's Day, has been around for over 50 years. The parade travels down Michigan Avenue through Corktown, which got its name from the large population of Irish immigrants from the County Cork who settled there in the mid-1800s. The annual Corktown Race is held before the parade.
 
Marche du Nain Rouge
Still a new event in Detroit's repertoire of ribald revelries, the Marche du Nain Rouge is the revival of an old tradition of driving out Detroit's "red devil," long considered a harbinger of doom and rumored to have appeared at the scene of every major catastrophe throughout Detroit's history. Costumed party-goers march through Midtown on the Sunday after the spring solstice to "drive out" the devil. What started with just a few hundred locals has grown into the thousands after just four years. The Marche is a distinctly Detroit version of Mardis Gras, with a Detroit-style DIY attitude. There is also a 5k run held before the march.
 
Tigers Opening Day
There ain't no party like a Deee-troit party, and at no time is this more evident than during the Detroit Tigers home opener. While every home game is a reason for Detroiters to celebrate (and they do, for an average of 1 in 4 days out of the year, rain or shine), the home opener is veritable Detroit holiday. 100,000 people descend upon downtown to tailgate, hit the bars and head to the game. Not a sportsfan? Not a problem. This is more just another reason to celebrate, and is the unofficial start of spring in Detroit.
 
Art X Detroit
Art X Detroit is a multidisciplinary celebration of Kresge Eminent Artists and Kresge Artist Fellows held throughout Midtown, Detroit's Cultural Center.
 
Wheelhouse Detroit
Wheelhouse Detroit is a bicycle retail, service and rental shop located on the Detroit Riverwalk in the Rivard Plaza. Buy a bike, get one fixed, or just rent one for a few hours, and don't miss out on their guided tours through Detroit's neighborhoods and scenic sites.
 
Detroit Restaurant Week
Held every spring and fall, Detroit Restaurant Week highlights some of Detroit's top dining destinations with 10 days of $30 prix fixe three-course dinners.
 
Metro Times Blowout
Launched in 1998 as the Hamtramck Blowout, the Metro Times Blowout is America's largest local music festival and has now extended into two weekends with more than 200 bands playing in dozens of venues in Detroit, Hamtramck and Ferndale.  
 
Motor City Brew Tours
By bus, bike, boat or foot, Motor City Brew Tours offers behind-the-scenes brewery tours year-round with an emphasis on biking and walking tours in the warmer months. For a fun road trip, check out their day trips to the breweries of Beer City USA: Grand Rapids.
 
Cinco de Mayo in Mexicantown
Southwest Detroit has a prominent Mexican population. Every year for Cinco de Mayo, the streets of Mexicantown fill with people for family-friendly festivities including floats, folklorico dancers, Latin bands and, of course, plenty of margaritas and Mexican pastries. There is also a Cinco de Mayo Fun Run & Walk in the morning.
 
SUMMER
 
Movement
Launched in 2000 as the Detroit Electronic Music Festival and switching producers' hands several times over the years before finding what seems to be long-term success with Paxahau, Movement continues to be one of the world's premiere electronic music festivals right here in the birthplace of techno music, Detroit. Movement is held every Memorial Day weekend in Hart Plaza.
 
Chevrolet Detroit Belle Isle Grand Prix
95,000 auto racing enthusiasts will head to Belle Isle the first weekend in June for the Chevrolet Detroit Belle Isle Grand Prix, featuring a number of racing events including the IndyCar Series and the Grand-Am Rolex Sports Car Series.
 
New Center Park
New Center Park hosts outdoor concerts (including everything from electronic to jazz and blues), film screenings and cultural festivals all summer long. Most events are free, though some are occasionally ticketed.
 
BravoBravo!
One of the premiere arts fundraising events for young professionals, BravoBravo! has the reputation of being the see-and-be-seen event of the year. All of Detroit's movers and shakers get dressed in their finest to hobnob and enjoy food, drink and live music for the Detroit Opera House's largest annual fundraiser.
 
Jazzin' on Jefferson
Held every June, Jazzin' on Jefferson is a project of the Jefferson East Business Association bringing food, art, retail and the best of local jazz to the east Jefferson corridor for a full festival weekend.
 
Detroit International Jazz Festival
Held annually on Labor Day weekend since 1980, this free jazz festival covers three blocks of Woodward Avenue with music, food and art, and is one of Detroit's most iconic annual events.
 
Hamtramck Labor Day Festival
For a totally different kind of flavor over Labor Day weekend, the Hamtramck Labor Day Festival features a kielbasa-eating contest, plenty of pierogi, and lots of polka.
 
Dally in the Alley
Summer isn't over yet! Dally in the Alley has been held the Saturday after Labor Day every year for over 35 years. The most local of Detroit festivals, Dally happens all over Midtown (once known as the Cass Corridor) with quirky Detroit vendors, musicians, food, and all the weird, random and wonderful things that make Midtown and Detroit unique.  
 
FALL
 
Tour de Troit
Starting out with under 100 riders in 2002, Tour de Troit now pulls in over 6,000 riders every September for the largest cycling event in the city. The ride ends at Roosevelt Park, where riders feast on food from Slows BAR BQ and drink lots of local beer.
 
Detroit Restaurant Week
Held every spring and fall, Detroit Restaurant Week highlights some of Detroit's top dining destinations with 10 days of $30 prix fixe three-course dinners.
 
Detroit Design Festival
The multi-day Detroit Design Festival presented by the Detroit Creative Corridor Center features exhibitions, installations, fashion shows, design competitions, workshops, studio tours and dozens of other coordinating events, including the signature Eastern Market After Dark. 
 
DLectricity
The inaugural event was held in 2012 and featured 35 nighttime projects (including site-specific installation projects, light sculptures and video projection) as well as coordinating events Detroit Gallery Week, Detroit Restaurant Week, and a "Light Bike" workshop and parade sponsored by Shinola, Detroit's own bicycle, watch, and leather goods manufacturer. DLectricity is part of the Detroit Design Festival.
 
Detroit Free Press Marathon
The annual Detroit Free Press Marathon is a 26.2-mile run held on the third Sunday every October. The race draws in nearly 20,000 runners from all over the country, crosses international boundaries and is a qualifier for the prestigious Boston marathon.
 
Michigan Brewers Guild Fall Beer Festival
The youngest of all the Michigan Brewers Guild festivals, this one is held at Eastern Market every October and now spans two days. Sample hundreds of different beers (many one-offs, limited releases and special reserves) from more than 60 different Michigan breweries.
 
Theatre Bizarre
It has been called one of the best Halloween parties in the country (organizers refer to it as "The Greatest Masquerade Party on Earth"), and with good reason: massive, elaborate set designs recall turn-of-the-century carnivals, and performances include top-talent burlesque, fire dancers, circus freaks, and noise/punk/shock/goth rock. Costumes are mandatory.
 
WINTER
 
North American International Auto Show
Held every January, the North American International Auto Show is one of the top auto shows in the world. Held at the COBO Center, which is currently undergoing a $300 million renovation, the NAIAS brings in over one million attendees to see the latest in automotive technology and upcoming releases from Detroit's Big Three and automakers from all over the world (exotic and concept cars offer additional excitement).
 
Motown Winter Blast
The Motown Winter Blast is a celebration of all things winter with ice skating, ice sculpture gardens, marshmallow roasting, and dog sledding, as well as live music, food vendors, comfort stations and a kids' zone.
 
The Dirty Show
This International Erotic Art Exhibition is held every February (always over Valentine's Day) and is one of the largest art shows of its kind in the world. The purpose of the Dirty Show is to promote, publish and propagate erotic art in all forms. See hundreds of juried art pieces (from the sensual to the macabre) and stay for performances that include burlesque, drag, and suspension acts.
 
Detroit Loves Cinema
Presented by Detroit Passport to the Arts in partnership with other cultural organizations, Detroit Loves Cinema is held every February around Valentine's Day and is becoming a popular winter event among Detroit's young professionals. Held at the Detroit Film Theatre inside the Detroit Institute of Arts, attendees get dressed for the red carpet, are photographed by the "paparazzi," then enjoy a screening of that year's Oscar-nominated short films.
 
Hamtramck Paczki Day
There's no centrally-organized authority for the annual Hamtramck Paczki Day celebrations (held every year on Fat Tuesday), but there is now a Paczki Day 5k Run (held the Saturday before) and all the bars in Hamtramck open early in the morning on the day itself, as do all the bakeries (which are known to get lines that extend for blocks). This is yet another unique-to-Detroit de facto holiday. Pro tip: paczek are available year-round at most Polish bakeries, so skip the lines and get yours in the days before.