2018 Pennsylvania House of Representatives election

The 2018 elections for the Pennsylvania House of Representatives was held on November 6, 2018, with all districts being decided. The term of office for those that were elected in 2018 began when the House of Representatives convened in January 2019. Pennsylvania State Representatives are elected for two-year terms, with all 203 seats up for election every two years. The election coincided with the election for Governor and one-half of the State Senate. The Republican Party maintained its majority in the House of Representatives despite receiving less than 45% of the popular vote.

35th legislative district
Democratic state representative Marc Gergely resigned his seat on November 6, 2017, after pleading guilty to charges regarding an illegal gambling machine ring. A special election for the 35th legislative district was held on January 23, 2018, to fill the seat.

Democrats selected Austin Davis, an assistant to Allegheny County executive Rich Fitzgerald, as their nominee. Republicans nominated Fawn Walker-Montgomery. Davis won the special election in the heavily Democratic district.

48th legislative district
Democratic state representative Brandon Neuman was elected to be a judge on the Washington County Court of Common Pleas in 2017. A special election to fill his House seat was held on May 15, 2018, in conjunction with the 2018 primary.

Democrats nominated attorney Clark Mitchell Jr, while Republicans nominated Afghan War veteran Tim O'Neal. Both candidates also ran for their respective party's nomination for the 2018 general election. Libertarian candidate Demosthenes Agoris also ran in this special election. O'Neal won the special election, flipping a seat into GOP hands.

68th legislative district
Republican state representative Matt E. Baker was appointed by President Donald Trump to serve in the U.S. Department of Health and Human Services in March 2018. A special election to fill his House seat was held on May 15, 2018, in conjunction with the 2018 primary.

Democrats nominated educator Carrie Heath, while Republicans nominated businessman Clint Owlett. Both candidates also ran for their respective party's nomination for the 2018 general election. Owlett won the special election in the heavily Republican district.

178th legislative district
Republican state representative Scott Petri was named executive director of the Philadelphia Parking Authority in December 2017. A special election to fill his House seat was held on May 15, 2018, in conjunction with the 2018 primary.

Democrats nominated Solebury Township supervisor Helen Tai, while Republicans nominated Council Rock School District board member Wendi Thomas. Both candidates also ran for their respective party's nomination for the 2018 general election. Tai defeated Thomas, flipping a seat for the Democrats, though Thomas would go on to win the seat back from Tai in the general election.

Close races
Districts where the margin of victory was under 10%: • #District 165, 0.5% (gain)

• #District 49, 0.56%

• #District 105, 1.64%

• #District 178, 1.66%

• #District 143, 1.68% (gain)

• #District 144, 1.94%

• #District 168, 2.34%

• #District 160, 2.94%

• #District 151, 2.98%

• #District 162, 3.1% (gain)

• #District 44, 3.68%

• #District 53, 4.21% (gain)

• #District 71, 4.28% (gain)

• #District 167, 4.3% (gain)

• #District 30, 4.54%

• #District 72, 4.84%

• #District 29, 5.4%

• #District 26, 5.58%

• #District 131, 5.64%

• #District 119, 6.12%

• #District 163, 6.84% (gain)

• #District 158, 6.88% (gain)

• #District 76, 7.44% (gain)

• #District 61, 7.52% (gain)

• #District 104, 8.96%

• #District 28, 9.1%

• #District 106, 9.16%

• #District 155, 9.3% (gain)

• #District 176, 9.48%

• #District 129, 9.95%

• #District 152, 9.98%

Results by district
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