The 1980 Houston Astros season was the 19th season for the Major League Baseball (MLB) franchise located in Houston, Texas, their 16th as the Astros, 19th in the National League (NL), 12th in the NL West division, and 16th at The Astrodome. The Astros entered the season having completed an 89–73 record for second place and games behind the division-champion Cincinnati Reds. At the time, this represented the closest the Astros had ever qualified for the playoffs.

On Opening Day, April 10, J. R. Richard made his fifth consecutive Opening Day start for Houston, who hosted the Los Angeles Dodgers and won, 3–2. On July 4, right-hander Nolan Ryan became the fourth major league hurler to record 3,000 career strikeouts.

Richard and left fielder José Cruz were selected to the MLB All-Star Game; Richard was the starting pitcher for the National League, and this was the first career selection for both players.

After a late collapse in 1979, the Astros completed their scheduled regular season with a record of 92–70, tying them for first place with Los Angeles after having lost three in a row in Los Angeles in the final series of the season. To determine the division champion, the teams played a tie-breaker on October 6, which the Astros won for the first division title and first time in franchise history to qualify for the playoffs. At the time, this also set the club record for wins in one season, surpassing the 89 from the season prior. Houston faced the Philadelphia Phillies in the National League Championship Series (NLCS), losing three games to two.

Following the season, The Sporting News recognized general manager Tal Smith as Executive of the Year, and Bill Virdon as Manager of the Year, the first Houston Astros personnel to win these awards.

Offseason October 12, 1979: Signed pitcher J. R. Richard to a four-year extension. October 26, 1979: Keith Drumright was sent by the Astros to the Kansas City Royals as the player to be named later to conclude the exchange started on April 27, 1979, in which the Astros received George Throop from Kansas City. November 19, 1979: Nolan Ryan was signed as a free agent by the Astros, for four seasons at $4 million total. Thus, Ryan become baseball's first million-dollar player. January 31, 1980: Joe Morgan was signed as a free agent by the Astros. A reunion for the two sides, Morgan made his major league debut with the Colt .45s in 1963 and patrolled second base for them through the 1971 campaign. February 21, 1980: Frank Riccelli was released by the Astros.

Regular season Summary Opening Day

+ Opening Day starting lineup Player Position 21 Terry Puhl Right fielder 12 Craig Reynolds Shortstop 28 César Cedeño Center fielder 8 Joe Morgan Second baseman 25 José Cruz Left fielder 23 Enos Cabell Third baseman 18 Art Howe First baseman 14 Alan Ashby Catcher 50 J. R. Richard Pitcher Venue: Astrodome • Final: Houston 3, Los Angeles 2 Sources:

On April 10, the Astros hosted the Los Angeles Dodgers for Opening Day, with J. R. Richard serving as the starting pitcher for the Astros. Richard carried a personal 11-game winning streak over Los Angeles into the start. Leadoff hitter and the first batter of the season for Houston Terry Puhl cranked a home run in the bottom of the first inning. In the bottom of the second, José Cruz replicated Puhl's feat with a home run leading off, and later that frame, Alan Ashby singled home Art Howe to stake Houston to a 3–0 lead. Cruz' home run was the second of his career on Opening Day, following his blast on April 7, 1975.

Meanwhile, Richard (1–0) started the new campaign in style by assembling a bid for a perfect game as the Dodgers took their at bat for the top of the seventh frame. He struck out Davey Lopes to retire the 19th consecutive batter and first of the seventh. Rookie Rudy Law then stroked a clean single to right field to simultaneously end perfect game and no-hit bids. Richard concluded with eight innings and surrendered just two hits and two runs—one unearned—while inducing 13 whiffs and departed with a 3–2 lead. Joe Sambito relieved and tossed a perfect ninth to preserve the Astros' victory and earn the save.

This Opening Day start extended Richard's then-club record for pitchers to five, which stood until Roy Oswalt took the mound for the 2008 opener. Meanwhile, Enos Cabell, who made the fifth and final of five uninterrupted Opening Day starts at third base for Houston, was just the third such player at the position for the club. Cabell succeeded Bob Aspromonte, who started each of the first seven in club history (1962 to 1968), and Doug Rader, who started each of the following seven (1969 to 1975).

Moreover, the victory represented Houston's eighth on Opening Day in 10 campaigns. This was the best such performance over any 10 season-span in club history, until the Astros reeled off a winning streak of ten Opening Day games from 2013 to 2022.

Rest of April Homerless the year prior, on April 11, Craig Reynolds belted his first of the year on an offering from Don Stanhouse leading off the eighth to ignite a five-run rally. This is enough to topple Los Angeles. Making his major league debut, Dave Smith earned the win in relief. During the eighth inning rally, Luis Pujols singled in two runs with the bases loaded, while Enos Cabell scored on the same play via an error, and Art Howe followed by doubling in Pujols.

In his debut as a Houston Astro on April 12, Nolan Ryan slugged a three-run home off Don Sutton of the Dodgers for the first of his major league career. The shot also accounted for half of the runs batted in (RBI) Ryan would accumulate that year. Though the blast gave Houston the lead, it did not hold as the game went all the way to 17 innings before Los Angeles claimed a 6–5 triumph. On the mount, Ryan went 6 innings, yielded 4 runs, 5 walks, and struck out three. Dave Smith (1–1) took the loss when he surrendered the go-ahead single to Mickey Hatcher that scored Dusty Baker during his fourth inning of work.

On April 15, Joe Niekro tossed a six-hit complete game victory over the Atlanta Braves, leading a 6–2 Astros win. His first win of the season, Niekro surrendered no bases on balls while striking out 6.

Richard fired a one-hitter of the Dodgers on April 19 in a 12-strikeout performance, notching his 13th consecutive triumph against the club. The lone hit surrendered to the Dodgers was an infield single by Reggie Smith during the fourth inning, while Richard's game score graded at 94. Bob Welch countered Richard nearly pitch-for-pitch, yielding Houston's only two hits in the fourth as well. However, Terry Puhl and César Cedeño both scored, resulting in the only tallies of the contest and 2–0 Astros win.

Ryan captured his first victory in an Astros uniform on April 22, leading an 8–0 shutout of the Cincinnati Reds at the Astrodome.He surrendered six hits, issued six walks, and whiffed seven over seven frames. Meanwhile, during the bottom of the first inning, José Cruz cranked a bases-loaded triple to opening the scoring—the first of three safeties—while finishing a home run short of hitting for the cycle. This was also Cruz' fifth career bout of five runs batted in (RBI) or more.

Following a stellar month of April, J. R. Richard earned National League (NL) Pitcher of the Month honors. It was also his second consecutive accolade, dating to September at the conclusion of the 1979 season. During five April starts, Richard went 4–0, 1.67 earned run average (ERA), and induced 48 whiffs over innings pitched (IP). Additionally, he suppressed hitters' success to a .104 batting average against (BAA) while limiting baserunners to a 0.717 walks plus hits per inning pitched (WHIP) and no home runs surrendered.

May With a 4–2 win on May 3, Astros manager Bill Virdon earned win number 356 as manager to take over the all-time franchise lead. The victory over the St. Louis Cardinals allowed Virdon to surpass Harry Walker, who led the club from 1968 to 1972.

Following a near-four hour rain delay on May 6 at Olympic Stadium in Montreal, the Astros left 8–4 winners over the Expos. José Cruz furnished four runs batted in (RBI) to propel the Astros' victory.

On May 18, Ryan hurtled both his first shutout and double-digit strikeout performance as an Astro, while reversing a personal three-game losing streak. Snaring a four-hitter, the Astros triumphed, 3–0, over the Philadelphia Phillies at home. Pete Rose—who knocked three hits—was the only Phillie whom Ryan was unable to solve. All of Houston's scoring took place during the first two frames, courtesy of an RBI from each of the first three batters in the order—Rafael Landestoy, Terry Puhl, and Jeffrey Leonard. Also his first complete game for the new team, Ryan's outing drew a game score of 85.

Enos Cabell singled home José Cruz during the second frame on May 28, and, from there, Nolan Ryan operated in complete command from start to finish, firing a two-hit, 1–0, shutout of the San Diego Padres. Ryan fanned seven and earned a game score of 85. This was Ryan's sixteenth career two-hit complete game, and first since June 18, 1979.

June—early July

In a 3–0 shutout of the Chicago Cubs on June 11, Astros starter J. R. Richard extended a scoreless innings streak to . The win capped the first-ever homestand sweep for the Astros after having swept 3 games each in series against the San Francisco Giants and Cubs. Richard's streak broke the franchise record, which stood until September 11, 2008, when Roy Oswalt went to innings after a 6–0 shutout win over the Pittsburgh Pirates.

Despite battling the flu, on June 16, Nolan Ryan hurled seven one-hit innings before reliever Joe Sambito closed out a 2–0 win over the St. Louis Cardinals. The Cardinals' only hit was a double in the third inning. Offensively, José Cruz plated both of the Astros' runs.

Richard yielded his first two home runs of the season on July 3 to the Atlanta Braves—which would also be the final two served of his career—hence, commencing the season without having surrendered any over the first 110 innings. Dale Murphy and Chris Chambliss took Richard deep back-to-back with two outs in the bottom of the sixth inning, for the first since Ray Knight on September 21, 1979. The Astros won, 5–3, and Richard obtained his 10th victory of the season, which would be the concluding of his career as well.

Nolan Ryan's 3,000th strikeout At Riverfront Stadium on July 4, Ryan became the fourth pitcher in major league history to record 3,000 strikeouts, joining Walter Johnson, Gaylord Perry, and Bob Gibson. During the bottom of the second inning, César Gerónimo of the Cincinnati Reds whiffed on a high inside fastball for the right-hander's historic marker. However, Cincinnati prevailed, 8–1. Over four innings, Ryan fanned six but walked seven.

Gerónimo was Ryan's third victim of the evening. In the first inning, Ken Griffey Sr. and Dan Driessen whiffed. In the second, Ray Knight worked a base on balls to turn over to Gerónimo. The center fielder fouled off an offering, took a ball, took a strike, then was retired swinging. The game momentarily paused as catcher Alan Ashby presented the ball to Ryan while 37,047 onlookers acknowledged the accomplishment with a standing ovation.

Ryan concluded the outing with 3,003 strikeouts, but with 1,173 bases on balls. His 13-year career record stood at 172–165.

MLB All-Star Game J. R. Richard was named the starting pitcher for the National League at the 51st All-Star Game, hosted at Dodger Stadium. There, Richard owned a career 7–2 record, and, on the season going into the break, had produced a 10–4 record, 1.96 ERA and 115 punchouts in frames. Richard became the Astros' first-ever pitcher to start an All-Star Game. He proceeded to toss two scoreless innings, fanned three hitters while navigating nine total batters faced. He also surrendered one hit and issued two bases on balls.