| Country: | Malaysia |
| Type: | parliamentary |
| Previous Election: | 1974 Malaysian general election |
| Previous Year: | 1974 |
| Previous Mps: | Members of the Dewan Rakyat, 4th Malaysian Parliament |
| Next Election: | 1982 Malaysian general election |
| Next Year: | 1982 |
| Seats For Election: | All 154 seats in the Dewan Rakyat |
| Elected Mps: | Members of the Dewan Rakyat, 5th Malaysian Parliament |
| Majority Seats: | 78 |
| Registered: | 5,059,689 |
| Turnout: | 75.30% |
| Election Date: | 8–22 July 1978 |
| Image1: | Tun Hussein Onn.jpg |
| Leader1: | Hussein Onn |
| Party1: | Barisan Nasional |
| Last Election1: | 60.81%, 135 seats |
| Seats1: | 130 |
| Seat Change1: | 5 |
| Popular Vote1: | 1,987,907 |
| Percentage1: | 57.23% |
| Swing1: | 3.58pp |
| Leader2: | Lim Kit Siang |
| Party2: | Democratic Action Party |
| Last Election2: | 18.32%, 9 seats |
| Seats2: | 16 |
| Seat Change2: | 7 |
| Popular Vote2: | 664,433 |
| Percentage2: | 19.13% |
| Swing2: | 0.81pp |
| Image3: | Mohammad Asri bin Muda.jpg |
| Leader3: | Asri Muda |
| Party3: | PAS |
| Last Election3: | 13 seats |
| Seats3: | 5 |
| Seat Change3: | 8 |
| Popular Vote3: | 537,720 |
| Percentage3: | 15.58% |
| Swing3: | – |
| Prime Minister | |
| Posttitle: | Prime Minister-designate |
| Before Election: | Hussein Onn |
| Before Party: | Barisan Nasional |
| After Election: | Hussein Onn |
| After Party: | Barisan Nasional |
General elections were held in Malaysia between Saturday, 8 July and Saturday, 22 July 1978.[1] Voting took place in all 154 parliamentary constituencies of Malaysia, each electing one Member of Parliament to the Dewan Rakyat, the dominant house of Parliament. State elections also took place in 276 state constituencies (except Kelantan, Sabah and Sarawak) on the same day.
It was Hussein Onn's first and only election since he became the country's third Prime Minister in 1976. His Barisan Nasional Party emerged victorious with 131 of the 154 seats in Parliament. Voter turnout was 75.3%.
As expected, Barisan Nasional comfortably maintained its majority in the Malaysian Parliament and thus, gave the Prime Minister the power to form a government with a free hand. Despite the victory, BN actually lost four seats out of 154 seats to the opposition.
The Pan-Malaysian Islamic Party (PAS) withdrew from BN in the midst of the 1977 Kelantan Emergency over disagreements with UMNO over the running of the state government of Kelantan, which PAS had controlled since the first post-independence general election in 1959. With the support of UMNO, detractors within PAS split with the party and formed the Pan-Malaysian Islamic Front (BERJASA). In the election, PAS lost the control of the state for the first time to the UMNO-BERJASA alliance within BN and keeping administration by BN for 12 years until 1990. Tengku Razaleigh Hamzah has been credited for UMNO's victory in Kelantan.
The opposition garnered 42.8% of total votes. In spite of that, the opposition as one won only 23 seats. Democratic Action Party won the largest slice of the pie among the opposition parties and hence, its leader Lim Kit Siang retained his position as the leader of the opposition that he had obtained four years earlier.
Candidates were returned unopposed in nine constituencies. The registered electors from these constituencies therefore did not cast ballots.