The MLB season is underway, and there’s still plenty of time to cash in with the best MLB betting promos from top sportsbooks. Today's MLB slate gets started early with marquee matchups like the Red Sox vs. Orioles at 2:35 p.m. ET and Rockies vs. Phillies at 3:05 p.m. ET; these MLB betting promos offer thousands in bonus value just for signing up and placing your first bet.
New users can unlock welcome offers like bonus bets, first-bet protection, and deposit matches—ideal for betting on today’s MLB action. Whether you’re wagering on moneylines, run lines, or player props, these sign-up promos give you added value from the start.
Sign up now using any of the MLB betting promos below to start betting on today's MLB odds. Don’t forget to check out our MLB predictions, best bets, and starting pitcher projections for today’s games.
Review the chart below to find the best MLB betting promos for you, then keep reading for expert picks and insights to bet smart today.
| Top MLB Sportsbooks | MLB Betting Promos for Opening Weekend | Sign-Up Link |
|---|---|---|
| bet365 | $150 Bet-and-Get or $1,000 First Bet Safety Net | TOPACTION |
| Fanatics Sportsbook | $300 Bet-and-Get Promo or $1,000 in No Sweat Bets | Click Here |
| BetMGM | Bet $10, Get $150 in Bonus Bets if You Win | ACTIONGET |
| Caesars Sportsbook | Get 10 100% Profit Boost Tokens | ACTION4DYW |
Top MLB Betting Promos, Predictions, and Probable Pitchers for March 31
1. bet365
- bet365 Bonus Code: TOPACTION
- bet365 Promo: $1,000 First Bet Safety Net or Bet $5, Get $150 in Bonus Bets, Win or Lose
- bet365 PA Promo: Bet $5, Get $150 in Bonus Bets + 50 Casino Spins, Win or Lose
- bet365 States Available: AZ, CO, IA, IL, IN, KY, LA, NC, NJ, OH, PA, TN, VA
Sign up with the bet365 bonus code TOPACTION to choose from two valuable MLB betting promos—either a bet $5, get $150 in bonus bets deal that pays out no matter the result, or a $1,000 First Bet Safety Net that refunds your first wager in bonus bets if it loses.
These bet365 sign-up promos are perfect for adding value to today's MLB action. With nearly every team in action, play our first bet on Royals vs. Brewers at 2:10 pm ET and secure funds to wager on the rest of the slate once your first wager settles.
If you're in Pennsylvania, the $150 bet-and-get offer is even better. PA residents get 50 spins for bet365 Casino on top of the $150 bonus when they sign up with the bet365 bonus code TOPACTION.
2. Fanatics Sportsbook
- Fanatics Sportsbook Promo: Click Here
- Fanatics Sportsbook Bet-and-Get Promo: Bet $30, Get $300 in Bonus Bets
- Fanatics Sportsbook Sign-Up Bonus: $1,000 in No Sweat Bets
- Fanatics Sportsbook NY Sign-Up Bonus: 300% Profit Boost Token
- Fanatics Sportsbook States Available: AZ, CO, CT, DC, IA, IN, KS, KY, LA, MA, MD, MI, NJ, OH, PA, TN, VA, VT, WV, WY
Fanatics Sportsbook has multiple Fanatics Sportsbook promo offers available to help you boost your MLB betting bankroll, including one of the most popular MLB betting promos on the market.
Fanatics Sportsbook’s headline offer gives new users up to $300 in bonus bets across their first three days on the platform.
Here’s how it works:
- Place a $10+ wager each day for three straight days
- After each qualifying wager settles, receive $100 in bonus bets
- That’s a total of $300 in bonus bets to use on any MLB wager, including props and totals
If you’re looking for more coverage, Fanatics Sportsbook also offers up to $1,000 in No Sweat Bets. This promo refunds losing No Sweat Bets—up to $100 per day—for 10 consecutive days, giving you more flexibility as you navigate early-season MLB betting.
New York bettors can also access an exclusive offer: a 300% Profit Boost Token on their first MLB wager. Follow the spest below to triple your profit in the Big Apple:
- Sign up and place a wager up to $50 on any MLB market
- If your bet wins, your profit is tripled—giving you a major payout boost
3. BetMGM
- BetMGM Bonus Code: ACTIONGET
- BetMGM Promo: Bet $10, Get $150 in Bonus Bets if You Win
- BetMGM Bonus Code: TOPTAN1600
- BetMGM Promo: 20% First Deposit Match, Up to $1,600 in Sports Bonus
- BetMGM Bonus Code: TOPACTION
- BetMGM Promo: $1,500 First Bet Offer
- BetMGM States Available: AZ, CO, DC, IA, IL, IN, LA, KS, KY, MA, MD, MI, NC, NJ, OH, PA, TN, VA, WV, WY
If you’re ready to jump into the MLB season, BetMGM Sportsbook is offering three valuable MLB betting promos, and you can pick the one that fits your betting style best.
Sign up with BetMGM bonus code ACTIONGET and place a $10+ first wager on any MLB market. If your bet wins, you receive $150 in bonus bets. This offer is available to new users in CO, MI, NJ, PA, and WV and is one of the best low-risk ways to get started.
Prefer to boost your bankroll with bonus funds? Register with BetMGM bonus code TOPTAN1600 in AZ, CO, DC, IN, IA, KS, KY, MA, MD, MI, NJ, NC, PA, TN, WV, or WY to get a 20% deposit match up to $1,600. A deposit of $10 or more qualifies you for bonus funds, though $8,000 is required to unlock the full bonus.
If you’re planning to place a larger wager, BetMGM’s First Bet Safety Net may be the better choice. Use BetMGM bonus code TOPACTION and get up to $1,500 back in bonus bets if your first bet loses. Available in AZ, DC, IA, IL, IN, LA, KS, KY, MA, MD, NC, OH, TN, VA, and WY, this offer refunds your stake in five equal bonus bet tokens.
4. Caesars Sportsbook
- Caesars Sportsbook Promo Code: ACTION4DYW
- Caesars Sportsbook Welcome Bonus: Bet $1, Get 10 100% Profit Boost Tokens
- Caesars Sportsbook States Available: AZ, CO, DC, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, NC, NJ, NY, OH, ON, PA, TN, VA, WV, WY
Doubling your profits on MLB bets is easier than ever, thanks to one of the top MLB betting promos available. Caesars Sportsbook is giving new users 10 Profit Boost Tokens. Just sign up with Caesars Sportsbook promo code ACTION4DYW and place a $1 first wager.
Here’s how to claim and use your Profit Boost Tokens:
- Register using the Caesars Sportsbook promo code ACTION4DYW
- Place a $1 first bet on any MLB market
- Instantly unlock 10 Profit Boost Tokens
- Apply each token on wagers up to $25 to double your profits on winning bets
These tokens are ideal for MLB betting, whether you’re wagering on moneylines, run lines, or player props. Just make sure to use them within 14 days of activation.
Alternative MLB Betting Promos
You don’t have to rely on traditional sportsbooks to have action on today's MLB games. Platforms like Kalshi and Underdog offer creative, engaging ways to back teams and players. So, whether you're trading outcomes or playing daily fantasy sports with MLB stars, the following platforms are great additions to the MLB betting promos above.
1. Kalshi Predictive Market
- Kalshi Promo Code: ACTION
- Kalshi Welcome Offer: Make $100 in Trades, Get $10 Sign-Up Bonus
- Kalshi States Available: 48 + Washington D.C. (Not available in New Jersey and Nevada)
Kalshi gives MLB fans a futures-style way to interact with the game. Instead of placing traditional bets, you trade on yes-or-no outcomes like “ AL East Winner?” or “ NL MVP Winner” The platform blends data and prediction in a clean, simple format that feels more like a stock market than a sportsbook.
Steps to claim your Kalshi bonus:
- Sign up using Kalshi promo code ACTION
- Make $100 worth of trades on any Kalshi market
- Receive a $10 bonus to keep trading and exploring
2. Underdog (DFS)
- Underdog Fantasy Promo Code: TOPACTION
- Underdog Fantasy Sign-Up Offer: 50% Deposit Match, Up to $1,000 in Bonus Funds
- Underdog Fantasy States Available: AL, AK, AZ, AR, CA, DC, DE, GA, IL, KS, KY, MA, MN, MO, NE, NM, NC, ND, OK, OR, RI, SC, SD, TN, TX, UT, VT, VA, WI, WV, WY
Step into the MLB DFS scene with Underdog, where you can enter daily drafts or create pick’em slips featuring players like Shohei Ohtani, Aaron Judge, and Juan Soto. It’s fast, intuitive, and fun for beginners and DFS veterans alike.
Use Underdog Fantasy promo code TOPACTION at signup, and Underdog matches 50% of your first deposit—up to $1,000. That means more chances to play, win, and build your bankroll all season long.
MLB Starting Pitchers & Predictions — Monday, March 31
The first pitch of today's slate is set to be thrown soon. Below are the starting pitchers for this afternoon's slate, along with predictions that you can use to maximize the MLB betting promos above.
Boston Red Sox vs. Baltimore Orioles
- Time/Location: 2:35 p.m. ET at Oriole Park at Camden Yards (Baltimore, MD)
- Starting Pitchers: Sean Newcomb (Boston Red Sox) vs. Cade Povich (Baltimore Orioles)
- Prediction: Orioles Team Total Over 4.5
The biggest edge in this matchup lies with the Orioles' offense, which remains stacked even without Gunnar Henderson. After averaging 4.9 runs per game last season, Baltimore is putting up six per game through four contests and exploded for nine-plus in both wins.
Adley Rutschman looks primed for a breakout year, while Jordan Westburg has opened the season red-hot with three home runs in 13 at-bats. The Orioles also benefit from recent ballpark changes—left field has been moved in and lowered, giving right-handed hitters like Rutschman, Westburg, and Ryan Mountcastle a more favorable hitting environment, especially against struggling lefty Sean Newcomb, who hasn’t been a regular starter since 2020.
While Cade Povich could deliver a solid outing, the best bet here is Baltimore scoring five or more runs in Monday’s home opener.
Colorado Rockies vs. Philadelphia Phillies
- Time/Location: 3:05 p.m. ET at T-Mobile Park (Seattle, Washington)
- Starting Pitchers: German Marquez (Colorado Rockies) vs. Cristopher Sanchez (Philadelphia Phillies)
- Prediction: Phillies -1.5 (-120)
The Phillies were dominant at home in 2024 with a 54-27 record and have a strong chance to keep that momentum going in a favorable matchup against the Rockies. Cristopher Sánchez, coming off a breakout season that earned him a top-10 finish in the NL Cy Young race, looked sharp in Spring Training and should thrive against a weak Colorado lineup.
Meanwhile, Rockies starter Germán Márquez projects as a league-average arm, and if the Phillies jump on him early, they get into a soft bullpen, setting the stage for another home win.
Use the best MLB betting promos now and tail one of both of these MLB best bets today.