[4] Based on a variant of the FCA Small Wide platform,[5] the 500L uses Fiat's Multiair variable valve timing engine technology and monovolume cab forward architecture:[6] a packaging concept that prioritizes passenger and cargo volume.

[7] Initially only available in a 2-row, 5-seat configuration, the lengthened 3-row, 7-seat variant, called the "500L Living", began production in 2013 for the European market.

Underscoring its increased length and overall size over other 500 variants, the suffix L denotes "large", "light" and "loft".

Two variants were projected, five and seven passenger, the latter originally targeted at North America but ultimately only marketed in Europe.

Fabrizio Vacca, senior interior designer with Fiat's Centro Stile in Turin described a "layered" theme with a base, a middle with expansive visibility and above that an available, very large, dual-pane panoramic sunroof.

The 500L's cab forward architecture[6] provides a total passenger and cargo volume of 121.1 cubic feet,[15] and features high H-point seating, tall roof and greenhouse, split front glass (A) pillar and polycarbonate rear (D) pillar,[16] making the Fiat 500L the first production vehicle to use polycarbonate windows.

The 500L's structural architecture uses 74% high strength steel (HSS) and complies with international safety standards.

With three front-end load (crash) dissipation paths the design has wide rear door openings; roof pillars that enable a 90% visibility for the driver's 360° field of view.

[18] The 500L uses shock absorbers (marketed as Koni Frequency Selective Damping (FSD) Technology) designed to filter out high-frequency suspension inputs from uneven road surfaces while maintaining ride control mechanically rather than electronically.

[21] In 2012, the 500L debuted formally at the Geneva Auto Show—followed by a media introduction at the Officine Grandi Riparazioni (OGR), the former Grand Repair Workshops of the Italian Railway, now a cultural center located at Corso Castelfidardo 22 in Turin—on 4 July, the day of the year when Fiat has historically introduced its 500 models.

Fiat Serbia inaugurated its reconstructed and renovated facilities in Kragujevac in April 2011—with production commencing 26 May 2012.

A co-located automotive supplier park includes sub-works for Magneti Marelli (exhaust and catalytic converters), Johnson Controls MM (instrument panels, interior, interior parts and plastic parts), Magneti Marelli (bumpers and spoilers), Dräxlmaier (electrical), with other works at the nearby Grosnica Supplier Park, including Johnson Controls (seats), PMC (suspension systems, sheet metal stampings and chassis assemblies), SIGIT (rubber and plastic parts) as well as HTL.

The entry level trim, typically marketed as Pop, includes electrically operated windows and door locks, Uconnect 5.0 system with 5-inch touchscreen interface, handsfree calling, Bluetooth-streaming audio, voice-controllable radio, hill start assist and a reconfigurable interior design marketed as Magic Cargo Space, which includes a three-level rear cargo floor panel, fold-flat front passenger seat as well as for-aft sliding, fold and tumble, reclining rear seating.

Upper trim levels (variously marketed as Easy, Sport, Pop Star or Lounge) include more standard features and numerous option packages, including satellite navigation, leather trim, heated front seats, dual-pane panoramic sunroof or fixed sunroof (Europe), 6.5" Uconnect system, roof colour options, fog lights, power outlets, illuminated visor mirrors and chrome trim.

[38] The 2014 Fiat 500L was tested by the Insurance Institute for Highway Safety (IIHS), and it received a Top Safety Pick award: For the U.S. introduction of the 500L, Fiat launched a commercial created by the Doner Company filmed in Old Salem, North Carolina[47] and starring Bryce Pinkham.

[48] For the 2013 launch of the 500L Trekking, Fiat broadcast a commercial by the agency Leo Burnett promoting its suitability for everyday adventuring.