I have an excel file containing data collected over many years as latitude and longitude coordinates for archaeological sites - how can I import it into QGIS as a new layer?
If you already have your data in excel make sure of the following a)Data must be in decimal degrees b)First row of the file has the name of the field (this is just an example)
then you have to save the file as a csv comma delimited (not msdos or mac). After opening Qgis you have to look for the "add delimited text layer plugin (a blue postit with commas icon).
You have to define that the delimiter is commas and choose the appropiate x and y fileds. When Qgis Opens the data it will ask for the CRS, you have to define the one for your data. The data you are looking in the image is latlon wgs 84, so I choosed EPSG4326. Once your data is loaded you can save the text layer to another type of file like shp. Hope it helps
This excellent tutorial explains how to do just that.
Note that if your data is in UTM:
You can follow the same process, but choose the appropriate UTM CRS in the Coordinate Reference System Selector instead of WGS84.
You can control your tabular data with XYtools plugin.
The aim of the xy-tools-plugin is to fill an x- and y-column of a given attribute table by clicking on a (reference) map. After 'filling the x and y column' you are able to export the table to a point shape file. Since version 0.2 you can also open Excel files, and using an x- and y-column load it as a Point layer.
In QGIS 3, I can recommend the plugin "Spreadsheet Layers" which worked very smoothly for me. No need for multiple steps or a tutorial! https://github.com/camptocamp/QGIS-SpreadSheetLayers
There's a tutorial here on importing CSVs or Spreadsheets: http://www.qgistutorials.com/en/docs/importing_spreadsheets_csv.html
There's an old question with answers here: Importing coordinate data from excel into QGIS?
And here's another tutorial: http://maps.cga.harvard.edu/qgis/wkshop/import_csv.php
Basically, you convert your file to a .csv and then use the 'Add delimited text layer' tool, available in the 'layer' -> 'add layer' toolbar.