Can we create a look up column from multiple lines of text column in list

Question

we need to create a lookup column from multiple lines of text column in SharePoint online list is it possible.

Answer 1

By design, the Multiple lines of text column type can not be used to create lookup columns.

Supported Column Types:

Single line of text

Number

Date and Time

Unsupported Column Types:

Multiple lines of text

Currency

Person or Group

Calculated

Hyperlink or Picture

Custom Columns

Yes/No

Choice

Lookup

Refer to: Create list relationships by using unique and lookup columns

Answer 2

My answer relies on the following conditions being true, if working in a classic mode list, given the scarcity of any other requirements in your question:

1. You are willing to have any rich formatting stripped out of the multi-line text field,
2. You are also willing to create a calculated field in the source list/library which will be limited to 255 characters - as a single line of text and

3. You are willing to permit that the lookup column only displays those 255 characters in the list with the look up column (the consumer list)

   • create a calculated column in you source list and select single line of text as the data type returned by the column. Name it whatever you like.

   • The formula should be:

   =LEFT([Multi-Line Text Field Name], 255)

   • Then create the lookup column on the Consuming List. The newly created calculated column should be present as a display value in the lookup column in the consuming list.