The L-series is a compact inline-four engine created by Honda, introduced in 2001 with the Honda Fit. It has 1.2 L (1,198 cc), 1.3 L (1,318 cc) and 1.5 litres (1,497 cc) displacement variants, which utilize the names L12A, L13A and L15A. Depending on the region, these engines are sold throughout the world in the 5-door Honda Brio Fit/Jazz hatchback Honda Civic and the 4-door Fit Aria/City sedan (also known as Fit Saloon). They can also be found in the Japanese-only Airwave wagon and Mobilio MPV.
 Two different valvetrains are present on this engine series. The L12A, L13A and L15A use (Japanese: i-DSI), or “intelligent Dual & Sequential Ignition”. i-DSI utilizes two spark plugs per cylinder which fire at different intervals during the combustion process to achieve a more complete burn of the gasoline. This process allows the engine to have more power while keeping fuel consumption low, thanks to the better gasoline utilization. Emissions are also reduced. The i-DSI engines have two to five valves per cylinder and a modest redline of only 6,000 rpm, but reach maximum torque at mid-range rpm, allowing for better performance without having to rev the engine at high speeds. The i-DSI is also known for not using Turbochargers in the performance category, as it uses a high compression, long stroke with a lightweight and compact engine.
 The other valvetrain in use is the VTEC on one of the two varieties of the L15A. This engine is aimed more at performance than efficiency with a slightly higher redline with 4 valves per cylinder, which reaches peak torque at higher rpm. However, it still offers a good combination of both performance and fuel efficiency. Both the i-DSI and VTEC have relatively high compression ratios at 10.8:1 and 10.4:1, respectively.
 Before April 2006, the L-series were exclusively available with a 5-speed manual transmission , continuously variable transmission (CVT) and dual clutch transmission (DCT). With the introduction of the Fit in Canada and the United States, an L-series engine was mated to a traditional automatic transmission with a torque converter for the first time. The L12A i-DSI is available exclusively in the European domestic market Jazz and is sold with only a 5-speed manual transmission.
 As of 2010, the L15A7 (i-VTEC) is a class legal engine choice for SCCA sanctioned Formula F competition, joining the 1.6L Ford Kent engine.
 In 2016 Honda introduced the L15B (DOHC-VTC-TURBO-VTEC) engine as part of their continuing global earth dreams strategy for lower emissions and higher fuel economy for a range of their cars, available with 6-speed manual and CVT transmissions with Earth Dreams Technology.
 This engine has been used since 2007 in Honda City CNG
 It debuted in Honda City/Fit Aria four door Sport-sedan in November 2002. 
 It debuted in JDM Fit and Mobilio Spike in September 2002.
 This engine has been used since 2009 in 2nd Gen Honda Jazz
 Honda Civic (FE1) (22+ USDM Base Model) 
 2023–present Acura Integra (DE4)
 Integrated Motor Assist (IMA) hybrid system, features Variable Cylinder Management (VCM)
 i-VTEC with Integrated Motor Assist (IMA) hybrid system
 Earth Dreams i-VTEC with Sport Hybrid i-DCD (intelligent Dual-Clutch Drive) system, operates in Atkinson-cycle
 Earth Dreams i-VTEC with Sport Hybrid “i-MMD” (Intelligent Multi Mode Drive) system, operates in Atkinson-cycle