I'd probably say Leotek comes first. RUUD Lighting/BetaLED comes in second. There was a Leotek SL-36W1R-FX in my town that's probably been there before 2007 because it still shows up on the 2007 street view here.

Leotek even made LED streetlights as early as 2004!

This is as difficult to answer as to name the inventor of the electric lamp.  That title is usually given jointly to Joseph Swan and Thomas Edison, but in fact working electric lamps were made by dozens of other individuals many decades before them.  Edison & Swan only achieved fame because they were the first to produce a commercially viable electric lamp - one that was affordable, bright enough and with a long enough life to meet consumer requirements.

The same is true of LED streetlights.  There were experiments dating back to at least the 1970s but their light output was pathetic and the cost was huge.  It took another three decades before LED streetlights became both functional and affordable.

I believe the credit for the worlds’ first commercially viable LED streetlights goes to the Belgian company Schréder, which in 2007 made perhaps the first effective and large-scale installation at the city of Split in Croatia/Hrvatska.  Just prior to that in 2006, Cree demonstrated advanced prototypes of high power white LED streetlamps that had been made possible by the invention of their Xlamp 7090 emitters, but I don’t think those were sold.

Interesting, although I would have guessed that 20 tonne thing Kev has got from DW Windsor?, with its “slow ramp up diodes” controlled by circuitry like something off the star ship Enterprise! 

I don’t know, but the WRTL Stela was the first mainstream LED lantern to become popular in the UK.   

The same is true of LED streetlights.  There were experiments dating back to at least the 1970s but their light output was pathetic and the cost was huge.  It took another three decades before LED streetlights became both functional and affordable.

I believe the credit for the worlds’ first commercially viable LED streetlights goes to the Belgian company Schréder, which in 2007 made perhaps the first effective and large-scale installation at the city of Split in Croatia/Hrvatska.  Just prior to that in 2006, Cree demonstrated advanced prototypes of high power white LED streetlamps that had been made possible by the invention of their Xlamp 7090 emitters, but I don’t think those were sold.

I remember my uncle a Electronics Engineer was excited reading in 1998 +/- about a BLUE LED with high enough efficiency / power output to "drive" phosphor coatings leading the way to a "proper white" LED
I believe CREE had retail white LED "engines" available commercially around 2000
I would "expect" the early LED street lights to show up around 02 - 04 window and Leotek has bean pointed out as 2004   

Ive seen somewhere that GE made the first led streetlights (in the 60s/70s?) but they were not used very much

As for the first worldwide one I believe that that would be the MOONCELL ENVIRO-LUM. The leotek (SLN?) would be my guess as to the first North American led streetlight.

BetaLED was the first. I worked for a lighting contractor that started installing these around 2009.

The leotek sln goes back to around 2004.

The SLN didn’t come out until 2009.

I believe that you are thinking of the FX, there are many pre 2007 examples of leotek SLNs.

I believe you’re mistaking between the two models, they look very similar.

Whooops, my mistake! Yes, the FX series was introduced around 2004, replaced by the SLN in 2009 which would be discontinued around 2012, replaced with the Greencobra. The SLN has a sag lens and a smaller LED array compared to the FX.  https://www.lighting-gallery.net/gallery/displayimage.php?album=search&cat=0&pos=2&pid=226990

As far as I remember Philips offered one of the first LED street lights in 2006/07 which was known as CityWing.

Most first affordable European LED street lights appeared in 2009. To name the most famous few are iGuzzini Achilede, Indal Stella, Philips SpeedStar… Schréder CIE introduced their first weird shaped LED lantern in early 2009 with the P186 which was not really a lantern to be sold on the market but to show the costumers that they are also exploring the new field of LEDs. A good example is their first large scale installation in Split, Croatia which marked a new dynamic light era back in 2008.